Filed by Unocal Corporation
                           pursuant to Rule 425 under the Securities Act of 1933
                                             Subject Company: Unocal Corporation
                                                     Commission File No.: 1-8483

GLASS LEWIS, PROXY GOVERNANCE RECOMMEND THAT UNOCAL STOCKHOLDERS VOTE IN FAVOR 
OF MERGER WITH CHEVRON

8/3/2005 2:19:50 PM
 
EL SEGUNDO, Calif., Aug 03, 2005 /PRNewswire-FirstCall via COMTEX/ -- Unocal
Corporation (UCL) today said that Glass Lewis & Co. and Proxy Governance, Inc.,
leading independent proxy advisory firms, have recommended that Unocal
stockholders vote for the merger with Chevron Corporation (CVX) at the special
meeting of Unocal stockholders scheduled for Aug. 10, 2005.

The recommendation is consistent with that of Institutional Shareholder
Services, which on Aug. 1, 2005, recommended that stockholders of Unocal vote in
favor of the Chevron merger.

In its Aug. 2, 2005, report, Glass Lewis stated, "The Unocal board pursued a
rigorous sale process: it engaged multiple interested in parties after being
approached by China National Offshore Oil Company Ltd. (CNOOC) in December 2004
and retained independent legal and financial experts to assist the board in its
process. We commend the board for its responsiveness."

In making its recommendation, Glass Lewis concluded that "after considering the
fair valuation, the lengthy evaluation conducted by the Unocal board as well as
the fact that CNOOC has withdrawn its bid, we believe that the proposed
agreement with Chevron warrants shareholder approval. Accordingly, we recommend
that shareholders vote FOR this proposal."

In its report published today, Proxy Governance also said that it supports the
Chevron transaction. The report said, "The merger appears to be joining two
companies with complementary assets, and we feel that the forecast synergies
appear to be attainable, which would help to improve the financial performance
of the combined company."

Commenting on the recommendations, Charles R. Williamson, Unocal chairman and
chief executive officer, said, "The fact that ISS, Glass Lewis and Proxy
Governance have recommended that our stockholders vote in favor of the
Unocal/Chevron merger reaffirms the board's view that the merger with Chevron is
in the best interest of Unocal stockholders. Unocal and its board continue to
urge all stockholders to follow these recommendations and vote for the merger
with Chevron."



About Glass Lewis & Co.

Glass Lewis & Co. is an analytical research and proxy advisory firm providing
services to institutional investors. The recommendations of Glass Lewis are
relied upon by hundreds of major institutional investment firms, mutual funds,
and other fiduciaries throughout the country to make informed investment and
proxy voting decisions.

About Proxy Governance, Inc.

Proxy Governance is a proxy advisory and voting firm that supports the growth of
long-term shareholder value through proxy analysis and recommendations that
favor the growth of overall corporate value.

About Unocal Corporation

Unocal is one of the world's leading independent natural gas and crude oil
exploration and production companies. The company's principal oil and gas
activities are in Asia and North America.

Additional Information for Investors

Chevron has filed a Form S-4, Unocal has filed a proxy statement and a
supplement to the proxy statement and both companies have filed and will file
other relevant documents concerning the proposed merger transaction with Chevron
with the Securities and Exchange Commission (SEC). INVESTORS ARE URGED TO READ
THE FORM S-4, PROXY STATEMENT, PROXY STATEMENT SUPPLEMENT AND ANY OTHER RELEVANT
DOCUMENTS FILED WITH THE SEC BECAUSE THEY CONTAIN IMPORTANT INFORMATION. You may
obtain the documents free of charge at the Web site maintained by the SEC at
www.sec.gov. In addition, you may obtain documents filed with the SEC by Chevron
free of charge by contacting Chevron 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.

Chevron, 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 proposed Chevron merger. Information about
the directors and executive officers of Chevron and their ownership of Chevron
stock is set forth in the proxy statement for Chevron's 2005 Annual Meeting of
Stockholders. Information about the directors and executive officers of Unocal
and their ownership of Unocal stock is 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, proxy statement and proxy statement supplement for the merger. Investors
should read the Form S-4, proxy statement and proxy statement supplement
carefully before making any voting or investment decisions.



Cautionary Information Regarding Forward-Looking Statements

This news release contains forward-looking statements about matters such as the
proposed merger transaction with Chevron. Although these statements are based
upon Unocal's current expectations and beliefs, they are subject to known and
unknown risks and uncertainties that could cause actual results and outcomes to
differ materially from those described in, or implied by, the forward-looking
statements, including volatility in commodity prices and other factors discussed
in Unocal's 2004 Annual Report on Form 10-K and subsequent reports filed or
furnished by Unocal with the SEC.

Copies of Unocal's SEC filings are available from Unocal by calling 800-252-2233
or from the SEC by calling 800-SEC-0330. The reports are also available on the
Unocal web site, www.unocal.com. Unocal undertakes no obligation to update the
forward-looking statements in this news release to reflect future events or
circumstances. All such statements are expressly qualified by this cautionary
statement, which is provided pursuant to the safe harbor provisions of Section
27A of the Securities Act of 1933 and Section 21E of the Securities Exchange Act
of 1934.

SOURCE Unocal Corporation

News Media, Barry Lane, +1-310-726-7731, or Investors, Robert Wright,

+1-310-726-7665, both of Unocal