EXHIBIT 99.1


                                  NEWS RELEASE

                                                               Company Contacts:
                                       Investors: Frank Hopkins or Chris Paulsen
                                      Media and Public Affairs:   Susan Spratlen
                                                                  (972) 444-9001

               Pioneer Agrees to Purchase Additional Interests in
                           Two Onshore U.S. Core Areas


Dallas,  Texas, June 28, 2005 -- Pioneer Natural  Resources  Company  (NYSE:PXD)
today announced that the Company has signed  agreements with two parties for the
purchase of additional assets in two of its U.S. onshore core areas, the Permian
Basin and South Texas, for a total purchase price of approximately $177 million.
Pioneer  is  purchasing   approximately  70  million  barrels  of  substantially
undeveloped   proved  oil   equivalent   reserves   with  daily   production  of
approximately  1,800  barrels  of oil  equivalent  (BOE)  and an  estimated  800
undrilled locations. The transactions are expected to close within 30 days.

Pioneer estimates that it will invest  approximately  $400 million over the next
five years to develop the acquired  proved  reserves,  accelerating  the pace of
drilling in each of these two core areas  beginning later this year. The Company
expects that production from the acquired assets could exceed 10,000 BOE per day
upon full development of the proved reserves.

Pioneer's  Chairman  and CEO,  Scott D.  Sheffield,  stated,  "We  already own a
minority  interest  in more  than 80% of the  producing  wells  and  development
locations  included  in these  acquisitions  and are very  pleased  to add these
low-risk  assets  to our  onshore  portfolio.  These  transactions  provide  new
opportunities  that are an excellent fit with our existing assets allowing us to
leverage our expertise,  consistent with our long-standing core area acquisition
strategy."

Pioneer is a large  independent oil and gas  exploration and production  company
with  operations in the United States,  Argentina,  Canada,  Equatorial  Guinea,
Nigeria, Sao Tome and Principe, South Africa and Tunisia. Pioneer's headquarters
are  in   Dallas.   For   more   information,   visit   Pioneer's   website   at
www.pioneernrc.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  that 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, product supply and demand, competition, government regulation or action,
the costs and results of drilling and operations, Pioneer's ability to implement
its business plans or complete its development projects as scheduled,  access to
and cost of capital,  uncertainties  about  estimates  of  reserves,  quality of
technical data and  environmental  and weather risks.  These and other risks are
described  in  Pioneer's  10-K and  10-Q  Reports  and  other  filings  with the
Securities and Exchange Commission.