EXHIBIT 10(o)

                        SANTA FE ENERGY RESOURCES, INC.

                                 David L. Hicks
                    Vice President, Law and General Counsel

                                 March 24, 1995

HC Associates
200 West Madison Street
27th Floor
Chicago, Illinois 60606

Re: Agreement Regarding Shelf Registration Statement

Gentlemen:

As we discussed, Santa Fe Energy Resources, Inc. (the "Company"), agrees that
upon the receipt of a written demand (which demand may be submitted to the
Company once, provided such registration is effected and the registration
statement is declared effective) from HC Associates, GKH Partners, L.P., GKH
Investments, L.P., Ernest H. Cockrell Texas Testamentary Trust or Carol Cockrell
Jennings Texas Testamentary Trust (collectively, the "Selling Stockholders") at
any time prior to March 27, 2000 to file with the Securities and Exchange
Commission (the "Commission") a registration statement on Form S-3 or such other
form as may be appropriate (the "Registration Statement") to register the offer
and sale, from time to time, by the Selling Stockholders of up to 5,203,091
shares of the Company's common stock, par value $0.01 per share, that are
beneficially owned by the Selling Stockholders as of the date hereof, plus such
additional number of shares of the Company's common stock that the Selling
Stockholders may own in the future as a result of any stock split, stock
distribution or stock dividend made by the Company (collectively, the "Shares").
Such agreement to register shall be subject to the following terms and
conditions:

      1. REGISTRATION PROCEDURES. Upon your demand, the Company will use its
reasonable best efforts to effect the registration and facilitate the sale and
distribution of all of the Shares or such portion thereof as the Selling
Stockholders may elect (the "Offered Securities") in accordance with the
intended method of disposition thereof and pursuant thereto the Company will as
expeditiously as reasonably possible, but subject to the provisions hereof:

      (a) prepare and file with the Commission a registration statement with
respect to such Offered Securities and use its reasonable best efforts to cause
such registration statement to become effective (provided that before filing a
registration statement or prospectus or any amendments or supplements thereto,
the Company will furnish on a timely basis to the counsel selected by the
Selling Stockholders copies of all such documents proposed to be filed, which
documents will be subject to the review of such counsel);

      (b) subject to the terms of paragraph 3, prepare and file with the
Commission such amendments, post-effective amendments and supplements to such
registration statement and the prospectus used in connection therewith as may be
necessary to keep such registration statement continuously effective for the
period required by the intended method of disposition or to describe the terms
of any offering made from an effective shelf registration, and comply with the
provisions of the Securities Act of 1993, as amended (the "Securities Act") with
respect to the disposition of all securities covered by such registration
statement during such period in accordance with the intended methods of
disposition by The Selling Stockholders set forth in such registration
statement;

      (c) furnish to the Selling Stockholders such number of copies of such
registration statement, each amendment, post-effective amendment and supplement
thereto, the prospectus included in such registration statement (including each
preliminary prospectus) and such other documents as the Selling Stockholders may
reasonably request in order to facilitate the disposition of the Offered
Securities; the Company consents to the use of the prospectus, including each
preliminary prospectus, by the Selling Stockholders in connection with the
offering and sale of the Offered Securities covered by the prospectus or the
preliminary prospectus;

      (d) use its reasonable best efforts to register or qualify such Offered
Securities under such other securities or blue sky laws of such jurisdictions as
the Selling Stockholders reasonably request and do any and all other acts and
things which may be reasonably necessary or advisable to enable the Selling
Stockholders to consummate the disposition in such jurisdictions of the Offered
Securities owned by the Selling Stockholders (provided that the Company will not
be required to (i) qualify generally to do business in any jurisdiction where it
would not otherwise be required to qualify but for this subparagraph, (ii)
subject itself to taxation in any such jurisdiction, (iii) consent to general
service of process in any such jurisdiction (unless the Company is subject to
service in such jurisdiction and except as may be required by the Securities
Act), or (iv) qualify such Offered Securities in a given jurisdiction where
expressions of investment interest are not sufficient in such jurisdiction to
reasonably justify the expense of qualification in that jurisdiction or where
such qualification would require the Company to register as a broker or dealer
in such jurisdiction);

      (e) promptly notify the Selling Stockholders at any time when a prospectus
relating thereto is required to be delivered under the Securities Act, of the
occurrence of any event as a result of which the prospectus included in such
registration statement contains an untrue statement of a material fact or omits
any material fact necessary, in light of the circumstances under which made, to
make the statements therein not misleading, and, at the request of the Selling
Stockholders and subject to the third paragraph of paragraph 3, the Company will
promptly prepare and furnish to the Selling Stockholders a supplement or
amendment to such prospectus so that, as thereafter delivered to the purchasers
of such Offered Securities, such prospectus will not contain an untrue statement
of a material fact or omit to state any material fact necessary, in light of the
circumstances under which made, to make the statements therein not misleading;

      (f) provide a transfer agent and registrar of all such Offered Securities
not later than the effective date of such registration statement and thereafter
maintain such a transfer agent and registrar, and otherwise cooperate with the
Selling Stockholders and any managing underwriter of such offering to facilitate
the timely preparation and delivery of certificates representing Offered
Securities to be sold, and enable such Offered Securities to be in such
denominations and registered in such names as the managing underwriter may
reasonably request at least two business days prior to any sale of Offered
Securities to the underwriters;

      (g) enter into such customary agreements (including underwriting
agreements in customary form) and take all such other actions as the Selling
Stockholders or the underwriters, if any, reasonably request in order to
expedite or facilitate the disposition of such Offered Securities, including,
without limitations:

      (i) making such representations and warranties to the underwriters in
form, substance and scope reasonably satisfactory to the managing underwriter
and the Company, as are customarily made by issuers to underwriters in primary
underwritten offerings;

      (ii) obtaining opinions (and, if required, updates thereof) of counsel,
which counsel and opinions (in form, scope and substance) shall be reasonably
satisfactory to the managing underwriter, if any, and addressed to the managing
underwriter covering the matters customarily covered in opinions requested in
underwritten offerings and such other matters as may be reasonably requested by
the managing underwriter;

      (iii) causing the underwriting agreements to set forth in full the
indemnification provisions and procedures of paragraph 2 (or such other
substantially similar provisions and procedures as the managing underwriter
shall reasonably request) with respect to all parties to be indemnified pursuant
to said paragraph; and

      (iv) delivering such documents (including causing the Company's
independent public accountants to furnish a customary "cold comfort" letter) and
certificates as may be reasonably requested by the Selling Stockholders to
evidence compliance with the provisions of this paragraph 1 and with any
customary conditions contained in the underwriting agreement or other agreement
entered into by the Company;

      (h) upon receipt by the Company of reasonable confidentiality agreements,
make available for inspection by any underwriter participating in any
disposition pursuant to such registration statement and any attorney, accountant
or other agent retained by any such underwriter, all financial and other
records, pertinent corporate documents and properties of the Company, and cause
the Company's officers, directors, employees and independent accountants to be
available on a reasonable basis and cooperate with such parties' "due diligence"
and to supply all information reasonably requested by any such underwriter,
attorney, accountant or agent in connection with such registration statement,
provided that the Company may refrain from disclosing any proprietary or other
information that is not material to the Company's financial condition or results
of operations;

      (i) in the event of the issuance of any stop order suspending the
effectiveness of a registration statement, or of any order suspending or
preventing the use of any related prospectus or suspending the qualification of
any Common Stock included in such registration statement for sale in any
jurisdiction, the Company will use its reasonable best efforts promptly to
obtain the withdrawal of such order; and

      (j) use its reasonable best efforts to cause the Offered Securities
covered by a registration statement to be registered with or approved by such
other governmental agencies or authorities as may be necessary by virtue of the
business and operations of the Company to enable the Selling Stockholders to
consummate the disposition of such Offered Securities.

      The Selling Stockholders agree that, upon receipt of any notice from the
Company of the occurrence of any event of the kind described in paragraphs 1(e)
or 1(i) hereof, the Selling Stockholders will forthwith discontinue disposition
of the Offered Shares until receipt of the copies of an appropriate supplement
or amendment to the prospectus under paragraph 1(e) or until the withdrawal of
such order under paragraph 1(i).

     2. INDEMNIFICATION.

      (a) The Company agrees to indemnify to the fullest extent permitted by
law, the Selling Stockholders, its officers, directors, stockholders, partners,
employees and directors and each person who controls (within the meaning of the
Securities Act) the Selling Stockholders against all losses, claims, damages,
liabilities and expenses whatsoever, as incurred, including any of the
foregoing, and reasonable fees and expenses of counsel incurred in
investigating, preparing or defending against, or aggregate amounts paid in
settlement of, any litigation, action, investigation or proceeding by any third
party or governmental agency or body, commenced or threatened, in each case
whether or not a party, or any claim whatsoever based upon, caused by or arising
out of any untrue or alleged untrue statement of a material fact contained in
any registration statement, prospectus or preliminary prospectus or any
amendment thereof or supplement thereto or any omission or alleged omission of a
material fact required to be stated therein or necessary to make the statements
therein not misleading, except insofar as the same are caused by or contained in
any information furnished in writing to the Company by the Selling Stockholders
(or on behalf of the Selling Stockholders) expressly for use therein or by the
Selling Stockholders' failure to deliver a copy of the registration statement or
prospectus or any amendments or supplements thereto after the Company has
furnished the Selling Stockholders with a sufficient number of copies of the
same. In connection with an underwritten offering, the Company will indemnify
such underwriters, their officers and directors and each person who controls
(within the meaning of the Securities Act) such underwriters to the same extent
as provided above with respect to the indemnification.

      (b) In connection with any registration statement in which any of the
Selling Stockholders is participating, the Selling Stockholders will furnish to
the Company in writing such information relating to the Selling Stockholders as
the Company reasonably requests for use in connection with any such registration
statement or prospectus and, to the fullest extent permitted by law, will
indemnify the Company, its directors, shareholders, employees and officers and
each Person who controls (within the meaning of the Securities Act) the Company
against any losses, claims, damages, liabilities and expenses whatsoever, as
incurred, including any of the foregoing, and reasonable fees and expenses of
counsel incurred in investigating, preparing or defending against, or aggregate
amounts paid in settlement of, any litigation, action, investigation or
proceeding by any third party or governmental agency or body, commenced or
threatened, in each case whether or not a party, or any claim whatsoever based
upon, caused by or arising out of any untrue or alleged untrue statement of a
material fact contained in the registration statement, prospectus or preliminary
prospectus or any amendment thereof or supplement thereto or any omission or
alleged omission of a material fact required to be stated therein or necessary
to make the statements therein not misleading, but only to the extent that such
untrue statement or omission is contained in any information so furnished in
writing by the Selling Stockholders expressly for such purpose and is reasonable
relied upon in conformity with such written information, or by the Selling
Stockholders' failure to deliver a copy of the registration statement or
prospectus or any amendments or supplements thereto after the Company has
furnished the Selling Stockholders with a sufficient number of copies of same.

      (c) Any person entitled to indemnification hereunder will (i) give
reasonably prompt written notice to the indemnifying party of any claim with
respect to which it seeks indemnification and (ii) unless in such indemnified
party's reasonable judgment a conflict of interest between such indemnified and
indemnifying parties may exist with respect to such claim, permit such
indemnifying party to assume the defense of such claim with counsel reasonably
satisfactory to the indemnified party. If such defense is assumed, the
indemnifying party will not be subject to any liability for any settlement made
by the indemnified party without its consent (but such consent will not be
unreasonably withheld). An indemnifying party who is not entitled to, or elects
not to, assume the defense of a claim will not be obligated to pay the fees and
expenses of more than one counsel for all parties indemnified by such
indemnifying party with respect to such claim, unless in the reasonable judgment
of any indemnified party a conflict of interest may exist between such
indemnified party and any other of such indemnified parties with respect to such
claim.

      (d) The indemnification provided for under this Agreement will remain in
full force and effect regardless of any investigation made by or on behalf of
the indemnified party or any officer, director or controlling Person of such
indemnified party and will survive the transfer of securities. The Company also
agrees to make such provisions, as are reasonably requested by any indemnified
party, for contribution to such party in the event the Company's indemnification
is unavailable for any reason. Such right to contribution shall be in such
proportion as is appropriate to reflect the relative fault of and benefits to
the Company on the one hand and the Selling Stockholders on the other, in
connection with the statements or omissions which result in such losses, claims,
damages, liabilities or expenses, as well as any other relevant equitable
considerations. The relative benefits to the indemnifying party and indemnified
parties shall be determined by reference to, among other things, the total
proceeds received by the indemnifying party and indemnified parties in
connection with the offering to which such losses, claims, damages, liabilities
or expenses relate. The relative fault of the indemnifying party and indemnified
parties shall be determined by reference to, among other things, whether the
action in question, including any untrue or alleged untrue statement of a
material fact or omission or alleged omission to state a material fact, has been
made by, or relates to information supplied by, such indemnifying party or the
indemnified parties, and the parties' relative intent, knowledge, access to
information and opportunity to correct or prevent such action.

      The parties hereto agree that it would not be just or equitable if
contribution pursuant hereto were determined by pro rata allocation or by any
other method of allocation which does not take account of the equitable
considerations referred to in the immediate preceding paragraph. No person found
guilty of any fraudulent misrepresentation (within the meaning of Section 11(f)
of the Securities Act) shall be entitled to contribution from any person who was
not found guilty of such fraudulent misrepresentation.

      3. UNDERWRITTEN OFFERINGS AND BLACK-OUT PERIODS. The Company agrees to
maintain an effective registration statement covering the Offered Securities
until the second anniversary of the date that such registration statement is
declared effective by the commission plus any additional periods represented by
any "Black-out Period" (defined below). The Selling Stockholders may request
permission from the Company to offer and sell Offered Securities pursuant to an
underwritten offering (an "Underwritten Offering") Any request (an "Underwriting
Request") for an Underwritten Offering shall be in writing and shall specify the
approximate number of Offered Securities to be included in such offering. Within
10 days after receipt by the Company of such Underwriting Request, the Company
will provide written notice to the Selling Stockholders indicating whether or
not it consents to such request.

      The Company shall be entitled to refuse its consent and to postpone the
commencement of any Underwritten Offering for a period of up to 180 days after
written notice to the Selling Stockholders of its refusal to consent to such
request based upon a determination made by the Company to promptly proceed to
prepare and file a registration statement (other than the registration pursuant
to which the offer and sale of the Offered Securities shall be registered or
registration statements on Form S-8 or other similar form) and the Company shall
be entitled to postpone for up to 90 days an Underwritten Offering if such
offering (y) would require disclosure of material information the Company has a
bona file business purpose of retaining as confidential or (z) have a material
adverse effect on the Company or its shareholders in relation to any financing,
acquisition, corporate reorganization or other material transaction contemplated
by the Board of Directors of the Company, involving the Company or any of its
affiliates, in each case as determined by the Company. The Company agrees to
notify the Selling Stockholders promptly upon its abandonment of any proposed
offering or other material transaction as described above, upon which
notification the Selling Stockholders shall be permitted to proceed with the
Underwritten Offering.

      The Selling Stockholders agree that if the Company has delivered
preliminary or final prospectuses to the Selling Stockholders and after having
done so (a) the Company determines that the prospectus needs to be amended or
supplemented to comply with the requirements of the Securities Act, (b) a stop
order suspending the effectiveness of the registration statement is issued by
the Commission or (c) the Company shall, in good faith and for business reasons,
enter into negotiations relating to or otherwise commence a material business
transaction, including, without limitation, the acquisition or divestiture of
assets or the offering or sale of securities, then the Company shall promptly
notify the Selling Stockholders and the Selling Stockholders shall immediately
cease making offers of the Shares and return all remaining prospectuses to the
Company. Following such amendment or supplement, the lifting of any stop order
or the completion or termination of any material transaction, the Company shall
promptly provide the Selling Stockholders with revised prospectuses and,
following receipt of the revised prospectuses, the Selling Stockholders shall be
free to resume making offers of the Offered Securities, or any portion thereof.

      The period during which the Company exercises its rights as described in
this paragraph 3 to postpone, delay or interrupt the offer and sale of the
Offered Securities or during the dependency of any stop order, injunction or
other order or requirement of the Commission or any other governmental agency or
court shall be referred to herein as a "Black-out Period."

      4. HOLDBACK AGREEMENTS. The Company agrees (a) not to effect any public
sale or public distribution of its equity securities, or any securities
convertible into or exchangeable or exercisable for such securities, during the
20-day period prior to and during the 120-day period beginning on the
commmencement date of any Underwritten Offering on behalf of the Selling
Stockholders (except pursuant to (i) registrations on Form S-8 or any successor
form, (ii) registrations on Form S-4 or any successor form, (iii) registrations
of securities in connection with a dividend reinvestment plan on forms(s)
applicable to such securities) unless the underwriters managing an Underwritten
Offering on behalf of the Selling Stockholders otherwise agree, and (b) to use
its reasonable best efforts to obtain agreements from its officers and directors
to agree not to effect any public sale or public distribution of any such
securities during such period (except as part of such underwritten registration,
if otherwise permitted), unless the underwriters managing the Underwritten
Offering on behalf of the Selling Stockholders otherwise agree.

      The Selling Stockholders agree not to effect any public sale or public
distribution of the Offered Securities, during the 20-day period prior to and
during the 120-day period beginning on the effective date of any underwritten
offering on behalf of the Company unless the underwriters managing such
underwritten offering on behalf of the Company otherwise agree; provided,
however, that the Company agrees that the Selling Stockholders need not comply
with the foregoing restriction unless the Company's directors, officers and
their 5% stockholders agree to a similar restriction in connection with such
underwritten offering.

      The Company will pay all costs and expenses of the registration of the
Shares (including any costs and expenses incurred, to amend or supplement the
prospectus, if required), except that the Selling Stockholders shall pay, and
the Company shall not pay, any underwriting or brokerage discounts or
commissions, any fees or disbursements of legal counsel for the Selling
Stockholders, or any of them, or transfer or other taxes attributable to the
registration or sale of the Shares.

      Each of the Selling Stockholders shall be required to furnish to the
Company such information regarding such Selling Stockholder and the distribution
proposed by such Selling Stockholder as the Company may request and as shall be
required in connection with any registration, qualification or compliance
referred to herein.

      If the foregoing is acceptable to you, please execute this letter and
enclosed duplicate in the space provided below and return one executed original
to me.

Very truly yours,

SANTA FE ENERGY RESOURCES, INC.

By: /s/ David Z. Hicks

Its: Vice President, Law and General Counsel

Agreed to and accepted

this the day of March 1995.

HC ASSOCIATES

By:

Its:

GKH INVESTMENT, L.P.

By:

Its:

GKH PARTNERS, L.P.

By:

Its:

ERNEST H. COCKRELL TEXAS

TESTAMENTARY TRUST

By:

Its:

CAROL COCKRELL JENNINGS TEXAS

TESTAMENTARY TRUST

By:

Its: