This document is being filed  pursuant to Rule 425 under the Securities Act
of  1933.  It  does  not  constitute  an  offer  for  the  sale  of  securities.
Shareholders  of HS  Resources,  Inc. and other  investors are urged to read the
proxy  statement/prospectus  in the registration  statement on Form S-4 filed on
May 30, 2001 by Kerr-McGee  Holdco,  Inc. in connection  with the merger.  These
materials  will  contain  important   information  about  HS  Resources,   Inc.,
Kerr-McGee  Corporation,  the merger,  the people soliciting proxies relating to
the merger, their interests in the merger and related matters.

     In   addition  to  the   registration   statement   containing   the  proxy
statement/prospectus filed in connection with the merger, HS Resources, Inc. and
Kerr-McGee  file annual,  quarterly and special  reports,  proxy  statements and
other information with the Securities and Exchange Commission.  You may read and
copy any reports, statements or other information filed by HS Resources, Inc. or
Kerr-McGee  Corporation at the SEC Public  Reference  Rooms at 450 Fifth Street,
N.W., Washington, D.C. 20549 or at any of the SEC's other public reference rooms
in New York and  Chicago.  Please  call the SEC at (800)  SEC-0330  for  further
information  on the public  reference  rooms.  Kerr-McGee  Corporation's  and HS
Resources,  Inc.'s  filings  with the SEC are also  available to the public from
commercial document-retrieval services and at the web site maintained by the SEC
at www.sec.gov.  Free copies of the proxy statement/prospectus,  and these other
documents  may also be obtained from  Kerr-McGee by directing a request  through
the investor  relations portion of Kerr-McGee's  website at Kerr-McGee.com or by
mail to Kerr-McGee  Corporation,  Investor Relations,  P.O. Box 25861,  Oklahoma
City, OK 713125.

     Statements  in  this  document  regarding  the  company's  or  management's
intentions,  beliefs or expectations including the number of ultimate prospects,
timing and order for drilling  prospects,  timing of  installation of production
facilities  and first  production  and  timing of  completion  of the merger are
"forward-looking  statements"  within the meaning of the  Securities  Litigation
Reform Act. Future results and developments discussed in these statements may be
affected by numerous factors and risks,  such as the accuracy of the assumptions
that  underlie  the  statements,  the  risk  that  the  businesses  will  not be
integrated  successfully,  the  success  of the  oil  and  gas  exploration  and
production program,  the price of oil and gas, drilling risks,  uncertainties in
interpreting   engineering   data,   demand  for  consumer  products  for  which
Kerr-McGee's  oil and gas business  supplies  raw  materials,  general  economic
conditions,  and other factors and risks discussed in the company's SEC filings.
Actual results and  developments  may differ  materially from those expressed or
implied in this document.




            Kerr-McGee Granted Early Termination of Hart-Scott-Rodino
            ---------------------------------------------------------
                  Waiting Period for HS Resources Acquisition
                  -------------------------------------------

     OKLAHOMA CITY (June 6, 2001) - Kerr-McGee Corp. (NYSE: KMG) announced today
that it has been  granted  early  termination  of the waiting  period  under the
Hart-Scott-Rodino  Antitrust  Improvements  Act of 1976,  in regards to the $1.7
billion acquisition of HS Resources, Inc. (NYSE: HSE).
     Kerr-McGee  announced  the  signing  of  a  definitive  agreement  with  HS
Resources  to acquire all of the  outstanding  shares of HS Resources on May 14,
2001.  The  agreement,  unanimously  approved by the boards of directors of both
companies, provides that Kerr-McGee will pay $66 for each share of HS Resources'
common stock. The payment  consists of 70% cash and 30% Kerr-McGee  common stock
issued at a fixed exchange ratio of .9404 shares for each share of HS Resources'
common stock.
     The  transaction,  which  is  subject  to  the  approval  of HS  Resources'
shareholders and other customary closing conditions, is expected to be completed
during the third quarter of this year.

                                      # # #

     (Statements  in this news release  regarding the company's or  management's
intentions,  beliefs  or  expectations  including  future  drilling  activities,
estimates of recoverable reserves and production, impact on operating costs, and
impact on earnings  and cash flow are  "forward-looking  statements"  within the
meaning of the Securities Litigation Reform Act. Future results and developments
discussed  in these  statements  may be affected by numerous  factors and risks,
such as the accuracy of the assumptions that underlie the statements, the actual
production volumes and costs, the final allocation of purchase price, the timing
and success of the oil and gas exploration, exploitation and production program,
the  price  of oil  and  gas,  drilling  risks,  uncertainties  in  interpreting
engineering  data,  general  economic  conditions,  and other  factors and risks
discussed in the  company's SEC filings.  Actual  results and  developments  may
differ materially from those expressed or implied in this news release.)

CONTACT: Debbie Schramm
         (405) 270-2877