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The following audio message from Charles R. Williamson to Unocal employees will
be posted on Unocal's internal internet site on April 4, 2005:


Hi, this is Chuck Williamson.

As you know from our recent press release and Newsline bulletin, we've just
signed a merger agreement with ChevronTexaco.

This was a difficult decision, but I am confident it is the right one. Combining
Unocal's assets and prospects with a much larger integrated company like
ChevronTexaco will strengthen both entities. ChevronTexaco has the financial and
technical resources to optimize the future potential of our assets, achieving a
level of value for our stockholders that we believe we could not achieve on our
own as an independent company.

In our negotiations with ChevronTexaco, it was clear that we have comparable
corporate cultures and share similar visions and values. It was also clear that
the leadership of ChevronTexaco has great respect for Unocal and our employees.

Unocal has a 115 year history as an independent company with a well-deserved
reputation for business integrity, operational excellence and technical
innovation. We can all be proud of what we've accomplished together. Our success
in building a strong portfolio of major international and deepwater projects has
created this exciting opportunity for Unocal to combine our operations with one
of the world's leading energy companies.

Joe, Terry, Sam and I know that the news of this agreement has raised a lot of
questions and concerns. A deal of this size and complexity will take many months
to complete, and we will do our best to provide timely answers to your questions
and keep you updated as we move ahead.

In the meantime, we have a business to run. We are still Unocal, and we have
obligations to our stockholders, our business partners, the communities that we
serve and ourselves to deliver against our plans for the year.

It is particularly important that we continue to do our work as safely and
responsibly as possible.

We know that each of you will be wondering what this merger means for you. It's
at times like these that we can become distracted, both at work and at home.





Safety is still our number one priority, now more than ever. Please pay special
attention to the safe behavior of yourself and your colleagues at work, at home,
and on the road.

I'm asking your help in ensuring that we fulfill our commitments and complete
this transaction smoothly and efficiently.

Thank you for your patience and support.





The following are questions and answers distributed by Unocal to its employees
on April 4, 2005.

--------------------------------------------------------------------------------
                                                                   April 4, 2005
                          COMMON QUESTIONS AND ANSWERS
               ABOUT UNOCAL'S ANNOUNCED MERGER WITH CHEVRONTEXACO
--------------------------------------------------------------------------------

Q.       WHY DID UNOCAL AGREE TO THIS TRANSACTION?

A.       ChevronTexaco (CVX) made an offer to acquire Unocal that our Board of
         Directors determined would be in the best interests of our stockholders
         to accept. Combining Unocal's assets and prospects within a much larger
         integrated company like CVX is expected to strengthen both entities. We
         believe that CVX possesses the financial and technical resources to
         maximize the future potential of our assets and prospects. In our
         conversations with CVX, it was also clear that we share similar values
         and have comparable corporate cultures.

Q.       WHEN WILL THE TRANSACTION BE COMPLETED AND THE CHANGE OF CONTROL TAKE
         PLACE?

A.       The process will take a number of months. We currently anticipate
         completing the transaction later this year, depending on the timing of
         receipt of all necessary regulatory and agency approvals, the approval
         by Unocal's stockholders of the transaction, and other matters.

Q.       WHAT WILL HAPPEN TO UNOCAL CORPORATION AND UNION OIL COMPANY?

A.       From an operational standpoint, our assets and activities will be
         consolidated into ChevronTexaco. We will become part of ChevronTexaco's
         operations.

Q.       HOW DOES THE TRANSACTION AFFECT OUR WORK?

A.       You should continue to do your job as efficiently and safely as
         possible. The transaction will take a number of months to complete.
         During this time, it is important that we continue to perform at a high
         level and not allow external events to distract us from safe,
         responsible and effective operations.

Q        HOW DOES THE TRANSACTION AFFECT THE DRIVE FOR HIGH PERFORMANCE?

A.       We will continue our work involving three themes: First, it has never
         been more important to focus on our World Class Safety initiative. Your
         safety and that of your colleagues is our number one priority during
         this time of transition. Second, continued progress on our Indonesia
         business strategy will be critical to our future as part of
         ChevronTexaco. Finally, we must continue our work in Thailand geared
         toward providing 1.6 BCFD to ensure that we are able to meet the
         growing energy demands of the Kingdom. Work on the other five themes of
         DHP will be brought to a close.

Q.       WHAT HAPPENS NEXT?

A.       CVX and Unocal will be forming a Transition Team. Members will be
         announced shortly. We will be seeking stockholder approval for the
         transaction as well as the necessary regulatory and agency approvals.
         Plans will be developed for integrating Unocal's assets, employees, and
         activities into CVX. We'll keep you informed as these developments move
         forward.





Q:       DO THE CHANGE OF CONTROL PROVISIONS APPLY TO ALL EMPLOYEES WORLDWIDE?

A.       The Unocal Change of Control provisions apply to all employees who are
         on the U.S. and U.S.O.L. payrolls. All employees worldwide who
         participate in Unocal's common stock and option-based compensation
         programs become fully vested at the time that Change of Control occurs.
         Other Change of Control benefits may apply to various employees,
         depending on their work locations and jurisdictions (Bangladesh,
         Northrock, Thailand, etc.). For those not on the U.S. or U.S.O.L.
         payrolls, your business unit manager or HR representative can provide
         additional information.

Q.       AT THE TIME OF THE MERGER, WHAT WILL BE THE STATUS OF UNOCAL EMPLOYEES?

A.       While ChevronTexaco's plans are to integrate Unocal's operations into
         its overall structure and portfolio, no specific decisions have been
         made at this time concerning personnel.

Q.       DO YOU ANTICIPATE LAY-OFFS ONCE THE MERGER IS COMPLETED?

A.       One of the factors that made CVX an attractive partner to management
         and the Board was CVX's appreciation of the skills and experience of
         our employees. CVX has indicated that they are motivated to retain
         employees. While it is likely that some employment reductions will
         occur, we do not know exactly what will happen at this time. We will
         work with CVX to establish a transition team and communicate with you
         as openly as possible during this process.

Q.       IF I RECEIVE A "COMPARABLE" JOB OFFER FROM CHEVRONTEXACO AND REFUSE TO
         TAKE IT , AM I STILL ELIGIBLE FOR CHANGE OF CONTROL BENEFITS?

A.       The answer is yes and no. You are eligible for all benefits relating to
         the vesting of stock and vesting in the retirement programs, but you
         will not receive any termination allowance or redeployment benefits if
         you refuse a comparable job offer. A comparable job offer is one that
         does not result in a reduction in base pay, or incentive targets, or a
         reduction in the aggregate value of benefits or require a work location
         change entailing a one-way commute increase of 50 miles or more.

Q.       WHAT ABOUT OUR EXISTING OFFICE LOCATIONS IN SUCH PLACES AS SUGAR LAND,
         TEXAS AND EL SEGUNDO AND BREA, CALIFORNIA. WILL THESE BE CLOSED OR
         RELOCATED?

A.       At this time, no plans to close or relocate specific offices have been
         developed.

Q.       WHAT ARE THE EFFECTS OF THIS MERGER ON EMPLOYEES AT THE TIME THE MERGER
         IS COMPLETED?

A.       Under Unocal's "Change of Control" provisions , among other things, the
         following will occur for employees on the U.S. or U.S.O.L. payrolls:

         (1)      Employee stock options and restricted stock vest.
         (2)      Participants in the Unocal Retirement Plan and Unocal Savings 
                  Plan will be 100% vested.
         (3)      Participants in the Annual Incentive Plan will receive a
                  payment based on his or her target percentage, pro-rated for
                  the portion of the calendar year completed as of the
                  completion of the merger.
         (4)      Recipients of Performance Share Awards would receive not less
                  than the shares awarded, multiplied by the merger price.
                  Payment would be in cash.





         (5)      Employees with balances in the Unocal Deferred Compensation
                  Plan would receive early distribution of pre-2005 plan
                  balances upon a change of control, if they have so elected.

Q.       WHAT IF AN EMPLOYEE IS LAID-OFF WITHIN TWO YEARS OF THE ACQUISITION OF 
         UNOCAL BY CVX?

A.       Under Unocal's "change of control" provisions, a terminated employee
         would receive, subject to the terms and conditions of the applicable
         severance plans, an enhanced severance benefit. Employees with less
         than 5 years of benefit service with Unocal would receive 4 months of
         base pay in a single payment under the Unocal Employee Redeployment
         Program benefit, plus a Unocal Termination Allowance Plan benefit of
         3/4 of a month for each completed year of service.

         An employee with 5 or more years of service would also receive the four
         months of base pay under the Unocal Employee Redeployment Program.
         However, the employee would have an enhanced Unocal Retirement Plan
         benefit in place of some or all of his or her enhanced Termination
         Allowance Plan benefit. The enhancement includes adding three years to
         the employee's age and service, a more favorable definition of pay and
         favorable actuarial factors. To the extent that this enhanced
         retirement benefit is less [on a lump sum basis] than the enhanced
         Termination Allowance Plan benefit, the employee would also receive the
         difference as cash payment.

         Below are a few examples of what employees might receive based on
         varying ages and amounts of benefit service.

                           ENHANCED BENEFIT EXAMPLES*
                   
                                                                                               
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
             AGE     YRS. OF      SALARY        RET. PLAN         REDEPLOYMENT        TERM.        TOTAL
                     SERVICE         $          ENHANCEMENT          BENEFIT          ALLOW      SEVERANCE
                                                     $                  $               $            $
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
1.           28         4         100,000            0                33,333          25,000       58,333
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
2.           30         5         100,000         13,975              33,333          17,275       64,583
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
3.           40         15        100,000         37,926              33,333          55,824      127,083
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
4.           50         25        100,000         91,591              33,333          64,659      189,583
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------
5.           60         25        100,000         73,924              33,333          82,326      189,583
---------- -------- ----------- ------------ ------------------ ------------------- ----------- -------------



o        The above only  illustrates  some of the  combination  of factors and
         potential pay-outs.  The allocation between retirement  enhancement and
         cash severance will vary based on the interest rate  applicable to lump
         sums. U.S. and U.S.O.L.  employees can evaluate their specific  benefit
         by going to the Change of Control section of myHR.

o        In addition to the above payments, employees are eligible for 
         out-placement and financial counseling benefits.

Q.       WILL CVX ELIMINATE THE UNOCAL "CHANGE OF CONTROL PROVISIONS"?

A.       Under the terms of the merger agreement, CVX has agreed to honor the
         Change of Control provisions of the plans.

Q.       HOW WILL ADDITIONAL DEVELOPMENTS AS TO THE TRANSACTION BE COMMUNICATED?

A.       We will try to keep you informed through a combination of newslines,
         web site updates, webcast presentations and town hall meetings. We will
         also develop more detailed written communications on individual benefit
         materials and other developments. Finally, we expect to update these
         questions and answers from time to time as we learn more information.





Q:       WHAT SHOULD EMPLOYEES DO NOW?

A:       We still have obligations to our stockholders, our business partners,
         the communities that we serve and ourselves to deliver against our
         plans for the year. It is also particularly important that we continue
         to do our work as safely and responsibly as possible. We know that each
         of you will be wondering what this merger means for you. It's at times
         like these that we can become distracted, both at work and at home.
         Safety is still our number one priority, now more than ever. Please pay
         special attention to the safe behavior of yourself and your colleagues
         at work, at home, and on the road.

Q:       WILL THIS CHANGE HOW UNOCAL CAN CONDUCT ITS BUSINESS BEFORE COMPLETING 
         THE MERGER?

A:       In general, we must continue to conduct our business in the ordinary
         course and to use our efforts to preserve our business organizations
         and third party relationships. We have also agreed not to take a number
         of actions without the consent of CVX during this time. These actions
         relate to matters such as stock issuances, changes to our benefit plans
         and arrangements and other compensatory matters, material asset
         acquisitions and dispositions, capital expenditures outside of our
         budget, incurring debt beyond a certain amount, waiving contractual
         rights, entering into new material agreements and taking other
         specified actions.

Note: The above description of benefit plans and merger documents are qualified
in their entirety by reference to the actual plans and agreements. In the event
of any conflict between the merger agreement and/or benefit plans, on the one
hand, and the above description, the merger agreement and/or benefit plans shall
govern.

ADDITIONAL INFORMATION FOR INVESTORS

Unocal will file a proxy statement and other relevant documents concerning the
proposed merger transaction with ChevronTeaco with the Securities and Exchange
Commission (SEC). INVESTORS ARE URGED TO READ THE PROXY STATEMENT WHEN IT
BECOMES AVAILABLE AND ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC BECAUSE
THEY WILL CONTAIN IMPORTANT INFORMATION. You will be able to obtain the
documents free of charge at the website maintained by the SEC at www.sec.gov. In
addition, you may obtain documents filed with the SEC by Unocal free of charge
by contacting Unocal Stockholder Services at (800) 252-2233, 2141 Rosecrans
Avenue, Suite 4000, El Segundo, CA 90245, e-mail:
stockholder_services@unocal.com.

Unocal, and its directors and executive officers, may be deemed to be
participants in the solicitation of proxies from Unocal's stockholders in
connection with the merger. Information about the directors and executive
officers of Unocal and their ownership of Unocal stock will be set forth in the
proxy statement for Unocal's 2005 Annual Meeting of Stockholders. Investors may
obtain additional information regarding the interests of such participants by
reading the proxy statement for the merger when it becomes available.

Investors should read the proxy statement carefully when it becomes available
before making any voting or investment decisions.





The following is an e-mail communication distributed to Unocal employees on
April 4, 2005.


INTERNAL BULLETIN

To:  All employees
From: Chuck Williamson

April 4, 2005

UNOCAL ACCEPTS CHEVRONTEXACO OFFER
----------------------------------

This morning, we issued a news release announcing that we had signed an
agreement for Unocal to be acquired by ChevronTexaco (CVX). The full text of the
news release follows this message.

The merger is the combination of two of the oldest oil and gas companies in the
United States - CVX has been in business for more than 125 years and Unocal for
nearly 115 years. Both companies are California-based with a global reach.

The decision to enter into the agreement was a difficult one. Like many of you,
I have worked most of my career with Unocal. I have invested 27 years with our
company, and I am proud of what we have accomplished together. We have a rich
history. Unocal is a company with a well earned reputation for business
integrity, operational excellence, and technical innovation.

In recent years, we've been highly successful in building a portfolio of major
international and deepwater assets and prospects. CVX has the financial and
technical resources to maximize the future potential of these projects. In our
discussions with CVX, it is clear that we share similar values and have
comparable corporate cultures. This merger will be a good fit.

Joe, Terry, Sam and I know that the news of this agreement may raise a lot of
questions and concerns. A deal of this size and complexity will take a number of
months to complete, and we will do our best to provide timely answers to your
questions and keep you updated as we move ahead.

In the meantime, we will be working with CVX to establish a transition team.
We have posted a preliminary list of questions and answers on the my.unocal.com
portal [link here]. Our Human Resources group has also posted detailed
information about Unocal's Change of Control Program. Employees on the U.S. and
U.S.O.L. payrolls can enter their employee ID number into the Change of Control
section of MyHR [link here] and view customized information on how the
transaction could impact them individually with regard to compensation and
benefits. The initial calculations on this website are based on 12/31/04
retirement data, but it will be refined over the next few weeks to allow you to
model different retirement dates.

Later this morning, CVX Chairman and CEO Dave O'Reilly and I will participate in
a conference call with security analysts and investment managers. You are
invited to 





listen to a webcast of that session beginning at 6:00 a.m. Pacific Time. See the
news release below for more information. Replays will be available for the next 
several days.

Later in the week, I will host a webcast update to Unocal employees about this
transaction. Details about this webcast will be distributed in the near future.

It is important for all of us to remember that we have a business to run. We are
still Unocal, and we have obligations to our stockholders, our business
partners, the communities that we serve and ourselves to deliver against our
plans for the year.

It is particularly important that we continue to do our work as safely and
responsibly as possible.

We know that each of you will be wondering what this merger means for you. It's
at times like these that we can become distracted, both at work and at home.

Safety is still our number one priority, now more than ever. Please pay special
attention to the safe behavior of yourself and your colleagues at work, at home,
and on the road.

I'm asking your help in ensuring that we fulfill our commitments and complete
this transaction smoothly and efficiently.

Thank you for your patience and support.

NEWS RELEASE

               CHEVRONTEXACO ANNOUNCES AGREEMENT TO ACQUIRE UNOCAL


O        STOCK AND CASH TRANSACTION VALUED AT $18 BILLION
O        ACQUISITION EXTENDS CHEVRONTEXACO'S STRATEGIC POSITIONS IN CORE AREAS
O        CHEVRONTEXACO PRODUCTION AND PROVED RESERVES EXPECTED TO INCREASE BY 
         MORE THAN 15 PERCENT

SAN RAMON, CALIF., APRIL 4, 2005 - ChevronTexaco Corporation (NYSE:CVX) and
Unocal Corporation (NYSE:UCL) announced today that ChevronTexaco would acquire
Unocal in a stock and cash transaction valued at approximately $18 billion,
including net debt. The acquisition, which is subject to approvals by Unocal
shareholders and certain regulatory agencies, will significantly enhance
ChevronTexaco's position as a leading global energy provider.

"Unocal is a unique independent with supermajor assets that are an excellent fit
with our existing portfolio and our long-term strategies - to grow profitably in
core upstream areas, build new legacy positions and commercialize our large
undeveloped natural gas resource base," ChevronTexaco Chairman and CEO Dave
O'Reilly said. "It is an attractive transaction that provides incremental value
in both the near- and long-term."

"Over the past several years Unocal has been highly successful in building a
portfolio of major international and deepwater assets and prospects," said
Charles R. Williamson, Unocal Chairman and Chief Executive Officer. "The
combination with ChevronTexaco 





will provide the financial and technical resources to maximize the potential of
these assets and prospects."

ChevronTexaco expects oil-equivalent production from the combined portfolios
during 2006 to average about 3 million barrels per day. Unocal's 1.75 billion
barrels of oil-equivalent proved reserves would increase ChevronTexaco's reserve
base as of the end of 2004 by about 15 percent. The resultant weighting of
natural gas reserves would increase by about 5 percentage points to roughly
one-third of the oil-equivalent total. ChevronTexaco expects the transaction to
be accretive to ChevronTexaco's prospective production growth rate.

STRONG STRATEGIC FIT
ChevronTexaco indicated the Unocal assets would provide an enhanced presence in
several of the company's core areas of operations, including:

o             ASIA PACIFIC - The combination of the two companies will place
              ChevronTexaco in the top tier of natural gas producers and
              marketers in this expanding and strategically important region.
              ChevronTexaco would become the top oil and gas producer in
              Thailand. In Indonesia, extensive oil and gas producing operations
              offshore in both the shelf and deepwater areas will augment
              ChevronTexaco's significant oil production, principally onshore.
              Unocal also markets through the Bontang LNG plant in Indonesia,
              complementing ChevronTexaco's current LNG production in Australia,
              as well as ChevronTexaco's planned development of natural gas
              fields in the greater Gorgon area of Australia and the shipment of
              LNG to markets in Asia and North America.

o             GULF OF MEXICO - The acquisition will enhance ChevronTexaco's
              position in the Gulf of Mexico, where it is already a leading
              participant on the shelf and in deepwater opportunities such as
              Tahiti, Jack, Blind Faith and Great White. This, when combined
              with Unocal's position on the shelf, its interests in Mad Dog, St.
              Malo, K2 and Puma in the deep water, and its portfolio of
              exploration acreage, will further strengthen ChevronTexaco's Gulf
              of Mexico profile.

o             CASPIAN REGION - The acquisition will give ChevronTexaco the
              second-largest interest in the Azerbaijan International Operating
              Company (AIOC) oil producing operations, broadening its status as
              a leading oil company in the Caspian region. With AIOC comes a
              share in the Baku-Tbilsi-Ceyhan (BTC) export pipeline, further
              expanding ChevronTexaco's position in Caspian oil export
              infrastructure.

SYNERGY OPPORTUNITIES
O'Reilly said the company would target synergies in a number of operations and
corporate functions by rationalizing duplicate activities and highgrading
investment programs. The integration process will focus on combining the
strengths of the two companies into a unified, high-performing enterprise. For
example, ChevronTexaco's proven expertise in project execution, particularly in
the deep water, will help leverage the full value of Unocal's major
developments. There will also be opportunities to add value by adopting Unocal's
operating best practices in ChevronTexaco.





ChevronTexaco expects disposition of assets following the close of the
transaction to result in proceeds of more than $2 billion. Annual savings from
operational synergies and reduced corporate expenses are estimated by
ChevronTexaco at more than $325 million before tax.

TERMS OF THE ACQUISITION
The acquisition consideration is structured as 75 percent stock and 25 percent
cash, providing an overall value of approximately $62 per share based on the
closing price of ChevronTexaco stock on April 1. Unocal shareholders may elect
to receive either 1.03 shares of ChevronTexaco stock or $65 in cash for each
share of Unocal stock; however, both of these elections will be subject to
proration. In the aggregate, ChevronTexaco will issue approximately 210 million
shares of ChevronTexaco stock and pay approximately $4.4 billion in cash.
ChevronTexaco will also assume estimated net debt of $1.6 billion.

EFFECTS ON FUTURE FINANCIAL RESULTS
ChevronTexaco estimates the acquisition would be accretive on a cash flow
per-share basis. Further, it will be broadly neutral to earnings per share after
taking into account synergies and significant additional share repurchases.
ChevronTexaco indicated plans for the repurchases, subject to board approval and
consistent with liquidity, legal requirements, and maintaining the company's AA
credit rating. Over the past year, ChevronTexaco repurchased $2.8 billion of its
common shares, as part of a $5 billion repurchase program.

INTEGRATION TIMETABLE
Following regulatory approval, the full integration of the two companies is
expected to be completed in six months.

"We have very strong integration capabilities following the merger of Chevron
and Texaco and intend to combine operations and achieve synergies quickly and
efficiently," O'Reilly said. "At the same time, we remain strongly focused on
enhancing our existing base business and increasing global production through
development of our strong queue of capital projects.

"ChevronTexaco and Unocal share common roots in the oil fields of California and
we believe we have highly compatible business cultures and values. A very
attractive element of this combination is the opportunity to integrate two
highly capable groups of employees to continue to drive world-class
performance," O'Reilly said.

Williamson said, "In our discussions with ChevronTexaco it is clear that we
share similar values and have comparable corporate cultures. This merger will be
a good fit."

O'Reilly concluded by saying, "The immediate benefits of this combination are
tangible and the longer-term value is even more compelling. We believe it will
significantly enhance our company's position as a leading competitor and the
partner-of-choice in the global energy industry."
                                      
                                     * * *

LEHMAN   BROTHERS  is  acting  as   financial   advisor  to   ChevronTexaco
Corporation.  PILLSBURY  WINTHROP  SHAW PITTMAN LLP is acting as legal  advisor.
MORGAN STANLEY & CO. INC. is acting as financial advisor to Unocal  Corporation.
WACHTELL, LIPTON, ROSEN & KATZ is acting as legal advisor to Unocal.





                                      * * *

ABOUT CHEVRONTEXACO
ChevronTexaco Corporation is one of the world's leading energy companies. With
more than 47,000 employees, ChevronTexaco subsidiaries conduct business in
approximately 180 countries around the world, producing and transporting crude
oil and natural gas, and refining, marketing and distributing fuels and other
energy products. ChevronTexaco is based in San Ramon, Calif. More information on
ChevronTexaco is available at www.chevrontexaco.com.

                                      * * *
ABOUT UNOCAL
Unocal is one of the world's leading independent natural gas and crude oil
exploration and production companies. With more than 6,000 employees, the
company's principal oil and gas activities are in Asia and North America. Unocal
has no refining or marketing operations.

                                      * * *

INVESTORS NOTE: A conference call to follow-up on the announcement of this
agreement will take place this morning, Monday, April 4, 2005, at 6:00 a.m. PDT.
A Webcast of the meeting will be available in a listen-only mode to individual
investors, media and other interested parties on ChevronTexaco's Web site at
www.chevrontexaco.com under the "Investors" heading and at (973) 582-2734.

MEDIA NOTE: A conference call for media with ChevronTexaco Chairman and CEO
along with Unocal Chairman and CEO, providing more details on the acquisition
will take place this morning, Monday, April 4, 2005 between 7:30 a.m. and 8:00
a.m. PDT. The call-in number is (973) 582-2757.

                                      * * *

CAUTIONARY STATEMENTS RELEVANT TO FORWARD-LOOKING INFORMATION
 FOR THE PURPOSE OF "SAFE HARBOR" PROVISIONS OF THE
 PRIVATE SECURITIES LITIGATION REFORM ACT OF 1995

Except for the historical and factual information contained herein, the matters
set forth in this press release, including statements as to the expected
benefits of the acquisition such as efficiencies, cost savings, market profile
and financial strength, and the competitive ability and position of the combined
company, and other statements identified by words such as "estimates, "expects,"
"projects," "plans," and similar expressions are forward-looking statements
within the meaning of the "safe harbor" provisions of the Private Securities
Litigation Reform Act of 1995. These forward-looking statements are subject to
risks and uncertainties that may cause actual results to differ materially,
including required approvals by Unocal shareholders and regulatory agencies, the
possibility that the anticipated benefits from the acquisition cannot be fully
realized, the possibility that costs or difficulties related to the integration
of Unocal operations into ChevronTexaco will be greater than expected, the
impact of competition and other risk factors relating to our industry as
detailed from time to time in each of ChevronTexaco's and Unocal's reports filed
with the SEC. You should not place undue 





reliance on these  forward-looking  statements,  which speak only as of the date
of this press release.  Unless legally required,  neither ChevronTexaco nor
Unocal   undertakes  no  obligation  to  update  publicly  any   forward-looking
statements, whether as a result of new information, future events or otherwise.

ADDITIONAL INFORMATION

ChevronTexaco will file a Form S-4, Unocal will file a proxy statement and both
companies will file other relevant documents concerning the proposed merger
transaction with the Securities and Exchange Commission (SEC). INVESTORS ARE
URGED TO READ THE FORM S-4 AND PROXY STATEMENT WHEN THEY BECOME AVAILABLE AND
ANY OTHER RELEVANT DOCUMENTS FILED WITH THE SEC BECAUSE THEY WILL CONTAIN
IMPORTANT INFORMATION. You will be able to obtain the documents free of charge
at the website maintained by the SEC at www.sec.gov. In addition, you may obtain
documents filed with the SEC by ChevronTexaco free of charge by contacting
ChevronTexaco Comptroller's Department, 6001 Bollinger Canyon Road - A3201, San
Ramon, CA 94583-2324. You may obtain documents filed with the SEC by Unocal free
of charge by contacting Unocal Stockholder Services at (800) 252-2233, 2141
Rosecrans Avenue, Suite 4000, El Segundo, CA 90245, e-mail:
stockholder_services@unocal.com.

ChevronTexaco, Unocal, and their respective directors and executive officers,
may be deemed to be participants in the solicitation of proxies from Unocal's
stockholders in connection with the merger. Information about the directors and
executive officers of ChevronTexaco and their ownership of ChevronTexaco stock
is set forth in the proxy statement for ChevronTexaco's 2005 Annual Meeting of
Stockholders. Information about the directors and executive officers of Unocal
and their ownership of Unocal stock will be set forth in the proxy statement for
Unocal's 2005 Annual Meeting of Stockholders. Investors may obtain additional
information regarding the interests of such participants by reading the Form S-4
and proxy statement for the merger when they become available.

Investors should read the Form S-4 and proxy statement carefully when they
become available before making any voting or investment decisions.

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