SECURITIES AND EXCHANGE COMMISSION
                              Washington, DC 20549



                                    FORM 8-K

                             Current Report Pursuant
                          to Section 13 or 15(d) of the

                         Securities Exchange Act of 1934



    Date of report (Date of earliest event reported)        May 25, 2000
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                               UNOCAL CORPORATION
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             (Exact name of registrant as specified in its charter)



                                    Delaware

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                 (State or Other Jurisdiction of Incorporation)



    1-8483                                   95-3825062
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(Commission File Number)                (I.R.S. Employer Identification No.)



2141 Rosecrans Avenue, Suite 4000, El Segundo, California         90245
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(Address of Principal Executive Offices)                       (Zip Code)



                                 (310) 726-7600

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              (Registrant's Telephone Number, Including Area Code)


Item 5.      Other Events.
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On May 25, 2000, the company completed the merger of its oil and gas exploration
and production assets in the Permian and San Juan basins with Titan Exploration,
Inc. (Titan), to create a new publicly traded company named Pure Resources, Inc.
(Pure).

The merger was  approved  by Titan  stockholders  at a special  meeting  held on
Wednesday,  May 24.  Titan  stockholders  will receive  .4302314  shares of Pure
common stock for each share of Titan common  stock.  Pure has  approximately  50
million common shares  outstanding.  The company now holds 65.4 percent, or 32.7
million  shares,  of  Pure,  and the  former  Titan  stockholders  will  own the
remaining 34.6 percent.  Pure's common stock began trading on the New York Stock
Exchange on May 26 under the "PRS" symbol.

The merger creates an independent  exploration  and production  company with pro
forma  combined  proved  reserves,  as of January 1, 2000,  of  approximately  1
trillion  cubic feet of natural gas  equivalent  (NGE),  80 percent of which are
proved, developed, and producing. Pure has net daily production of approximately
230 million  cubic feet of NGE.  About 60 percent of this  production is natural
gas, and 40 percent is oil. Pure is headquartered in Midland, Texas.

The company will fully consolidate the financial and operating results of Pure.


Forward-looking  statements  regarding  business and market  transactions,  cost
reductions,  and estimates of production  and reserve  quantities in this filing
are  based  on  assumptions   concerning   operational,   market,   competitive,
regulatory, environmental, and other considerations. Actual results could differ
materially  as a result of factors  discussed  in Unocal's and Titan's 1999 Form
10-K reports and their combined proxy statement/prospectus dated April 19, 2000.

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Pursuant  to the  requirements  of the  Securities  Exchange  Act of  1934,  the
registrant  has duly  caused  this  report  to be  signed  on its  behalf by the
undersigned, thereunto duly authorized.

                                                UNOCAL CORPORATION
                                                (Registrant)





Date:  May 31, 2000                        By:  /s/ JOHN A. BRIFFETT
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                                                John A. Briffett
                                                Assistant Comptroller


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