EXHIBIT 99.1


                                  NEWS RELEASE


             Pioneer Closes Sale of Deepwater Gulf of Mexico Assets

March 29, 2006 -- Pioneer Natural Resources Company  (NYSE:PXD)  announced today
that its  wholly-owned  subsidiary,  Pioneer  Natural  Resources  USA, Inc., has
closed the sale of certain  deepwater Gulf of Mexico assets to Marubeni Offshore
Production (USA) Inc., a subsidiary of Marubeni  Corporation,  for cash proceeds
of $1.3 billion before normal closing  adjustments which are currently estimated
to be  approximately  $140 million.  Pioneer expects to record an after-tax gain
associated with the sale of approximately $425 to $475 million.

The transaction includes Pioneer's interests in three producing projects (Falcon
Corridor,  Devils Tower and Canyon Express),  two potential development projects
(Ozona Deep and Thunder Hawk) and 87 exploration  blocks.  One exploration block
was  removed  from the  sale to  Marubeni  due to a  third-party  exercise  of a
preferential right to purchase the block.

Pioneer is retaining  its 55% operated  interest in Green Canyon  Blocks 299 and
300 where it drilled the Clipper  discovery  announced in October 2005.  Pioneer
plans to develop this field and has a rig contracted to drill appraisal wells in
the third quarter.

Pioneer  expects to use a portion of the proceeds to initiate the  repurchase of
the remaining $359 million of shares  authorized under its previously  announced
$1  billion  share  repurchase  program.  Proceeds  will  also be used to reduce
short-term  debt and fund a portion of its 2006 capital  budget which is focused
primarily  on North  American  onshore  development  activities  and  lower-risk
resource plays.

During  December  2005, the Company's net daily  production  from the properties
being divested averaged approximately 38,000 barrels oil equivalent.

Pioneer is a large  independent oil and gas exploration and production  company,
headquartered in Dallas, Texas, with operations in the United States, Canada and
Africa. For more information, visit Pioneer's website at www.pxd.com

Except for historical  information contained herein, the statements in this News
Release are forward-looking statements that are made pursuant to the Safe Harbor
Provisions   of  the  Private   Securities   Litigation   Reform  Act  of  1995.
Forward-looking  statements and the business prospects of Pioneer are subject to
a number of risks and uncertainties  which may cause Pioneer's actual results in
future periods to differ materially from the forward-looking  statements.  These
risks and uncertainties include,  among other things,  volatility of oil and gas
prices,  government  regulation or action, the costs and results of drilling and
operations,  Pioneer's  ability to implement its business  plans  (including its
plans to  repurchase  stock  at  favorable  prices)  and  access  to and cost of
capital.  These and other risks are described in Pioneer's 10-K and 10-Q Reports
and other filings with the Securities and Exchange Commission.

Company Contacts:
Pioneer Natural Resources                          Marubeni Offshore Production
Investors: Frank Hopkins or Chris Paulsen            (USA) Inc.
Media and Public Affairs:  Susan Spratlen          Matthew Cabell
(972) 444-9001                                     (832) 379-1100