EXHIBIT 99.1



                                  NEWS RELEASE

                                                   Investor Relations Contacts:
                               Susan Spratlen or Chris Paulsen   (972) 444-9001


                Pioneer Announces Executive Changes in Argentina

Dallas,  Texas, January 27, 2005 -- Pioneer Natural Resources Company (NYSE:PXD)
today  announced  that  Guimar Vaca Coca,  President  of Pioneer  Argentina,  is
retiring  after 12 years with  Pioneer and its  predecessors.  Vaca Coca has led
Pioneer's Argentine Division through an extensive period of sustained production
growth, successfully navigating a difficult political and fiscal environment and
emerging with a strong outlook for continued growth in production,  reserves and
profitability.

Pioneer has appointed  Marcelo D. Guiscardo to succeed Vaca Coca as President of
Pioneer  Argentina.  Guiscardo has 25 years of experience in the industry,  most
recently as President of San Antonio, a Buenos Aires-based  service company that
is a Latin American  division of Pride  International  Ltd. His prior experience
includes six years as Vice President of Business  Development and Vice President
of Exploration  and  Production  with YPF S.A. in Buenos Aires and 14 years with
Exxon, principally in exploration and production. He holds a Bachelor of Science
degree in Civil  Engineering from Rutgers  University.  Guiscardo will report to
Tim Dove, President and COO.

Scott Sheffield,  Chairman and CEO, stated, "Guimar has been a strong steward of
Pioneer  Argentina for many years and an integral part of the Company's  overall
success.  We wish him much  happiness in his  retirement  and his plans to spend
more time with his family and friends."

"We are excited to welcome  Marcelo to the Pioneer  team and are pleased to have
someone with such extensive industry  experience to fill this important position
in Argentina.  With the potential  for  significant  growth in both reserves and
value,  this  division  will  continue to play an  important  role in  Pioneer's
value-added growth strategy," added Tim Dove, President and COO.

Pioneer is a large  independent oil and gas  exploration and production  company
with  operations in the United States,  Argentina,  Canada,  Equatorial  Guinea,
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,
international  operations  and associated  international  political and economic
instability,  litigation,  the costs and  results of  drilling  and  operations,
Pioneer's ability to replace reserves, 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,
environmental and weather risks, acts of war or terrorism. These and other risks
are  described  in Pioneer's  10-K and 10-Q  Reports and other  filings with the
Securities and Exchange Commission.