<PAGE>

                                                                   EXHIBIT 10.10


                                 $350,000,000

                             PURE RESOURCES, INC.

                         7 1/8% Senior Notes due 2011



                         REGISTRATION RIGHTS AGREEMENT
                         -----------------------------

                                                                    June 5, 2001

Credit Suisse First Boston Corporation
First Union Securities, Inc.
BNP Paribas Securities Corp.
Fleet Securities, Inc.
Credit Lyonnais Securities (USA) Inc.
BNY Capital Markets, Inc.
Wells Fargo Brokerage, LLC
c/o Credit Suisse First Boston Corporation
  Eleven Madison Avenue
  New York, New York 10010-3629

Dear Sirs:

     Pure Resources, Inc., a Delaware corporation (the "Issuer"), proposes to
issue and sell to Credit Suisse First Boston Corporation and First Union
Securities, Inc. (collectively, the "Initial Purchasers"), upon the terms set
forth in a purchase agreement of even date herewith (the "Purchase Agreement"),
$350,000,000 aggregate principal amount of its 7?% Senior Notes due 2011 (the
"Initial Securities") to be guaranteed (the "Guaranties") by Titan Exploration,
Inc., a Delaware corporation, Pure Resources Holdings, Inc., a Nevada
corporation, Pure Resources, L.P., a Texas limited partnership, Pure Resources
I, Inc., a Delaware corporation, PK I, L.P., PK II, L.P., PK III, L.P., PK IV,
L.P., HEP Pure, LP and Hallwood Energy Partners, L.P., each of which is a
Delaware limited partnership, Pure GP, LLC, a Delaware limited liability
company, Pure Resources Holdings, LLC, a Nevada limited liability company,
Hallwood Petroleum, Inc., a Delaware corporation, HEP Pure Acquisition, LLC, a
Delaware limited liability company, La Plata Associates, LLC, a Colorado limited
liability company, and Hallwood La Plata, LLC, a Colorado limited liability
company (the "Guarantors" and, collectively with the Issuer, the "Company").
The Initial Securities will be issued pursuant to an Indenture, dated as of June
8, 2001 (the "Indenture"), among the Issuer, the Guarantors named therein and
First Union National Bank, as trustee  (the "Trustee").  As an inducement to the
Initial Purchasers to enter into the Purchase Agreement, the Company agrees with
the Initial Purchasers, for the benefit of the Initial Purchasers and the
holders of the Securities (as defined below) (collectively the "Holders"), as
follows:
<PAGE>

     1.   Registered Exchange Offer.  Unless not permitted by applicable law
(after the Company has complied with the ultimate paragraph of this Section 1),
the Company shall prepare and, not later than 120 days (such 120th day being a
"Filing Deadline") after the date on which the Initial Purchasers purchase the
Initial Securities pursuant to the Purchase Agreement (the "Closing Date"), file
with the Securities and Exchange Commission (the "Commission") a registration
statement (the "Exchange Offer Registration Statement") on an appropriate form
under the Securities Act of 1933, as amended (the "Securities Act"), with
respect to a proposed offer (the "Registered Exchange Offer") to the Holders of
Transfer Restricted Securities (as defined in Section 6 hereof), who are not
prohibited by any law or policy of the Commission from participating in the
Registered Exchange Offer, to issue and deliver to such Holders, in exchange for
the Initial Securities, a like aggregate principal amount of debt securities of
the Company issued under the Indenture, identical in all material respects to
the Initial Securities (except for the transfer restrictions relating to the
Initial Securities) and registered under the Securities Act (the "Exchange
Securities").  The Company shall use its commercially reasonable best efforts to
(i) cause such Exchange Offer Registration Statement to become effective under
the Securities Act within 180 days after the Closing Date (such 180th day being
an "Effectiveness Deadline")  and (ii)  keep the Exchange Offer Registration
Statement effective for not less than 30 days (or longer, if required by
applicable law) after the date notice of the Registered Exchange Offer is mailed
to the Holders (such period being called the "Exchange Offer Registration
Period").

     If the Company commences the Registered Exchange Offer, the Company (i)
will be entitled to consummate the Registered Exchange Offer 30 days after such
commencement (provided that the Company has accepted all the Initial Securities
theretofore validly tendered in accordance with the terms of the Registered
Exchange Offer) and (ii) will be required to consummate the Registered Exchange
Offer no later than 40 days after the date on which the Exchange Offer
Registration Statement is declared effective (such 40th day being the
"Consummation Deadline").

     Following the declaration of the effectiveness of the Exchange Offer
Registration Statement, the Company shall promptly commence the Registered
Exchange Offer, it being the objective of such Registered Exchange Offer to
enable each Holder of Transfer Restricted Securities (as defined in Section 6
below) electing to exchange the Initial Securities for Exchange Securities
(assuming that such Holder is not an affiliate of the Company within the meaning
of the Securities Act, acquires the Exchange Securities in the ordinary course
of such Holder's business and has no arrangements with any person to participate
in the distribution of the Exchange Securities and is not prohibited by any law
or policy of the Commission from participating in the Registered Exchange Offer)
to trade such Exchange Securities from and after their receipt without any
limitations or restrictions under the Securities Act (other than the prospectus
delivery requirements referred to in clause (i) of the next paragraph, if and to
the extent applicable) and without material restrictions under the securities
laws of the several states of the United States.

     The Company acknowledges that, pursuant to current interpretations by the
Commission's staff of Section 5 of the Securities Act, in the absence of an
applicable exemption

                                      -2-
<PAGE>

therefrom, (i) each Holder that is a broker-dealer electing to exchange Initial
Securities, acquired for its own account as a result of market making activities
or other trading activities, for Exchange Securities (an "Exchanging Dealer"),
is required to deliver a prospectus containing the information set forth in (a)
Annex A hereto on the cover, (b) Annex B hereto in the "Exchange Offer
Procedures" section and the "Purpose of the Exchange Offer" section, and (c)
Annex C hereto in the "Plan of Distribution" section of such prospectus in
connection with a sale of any such Exchange Securities received by such
Exchanging Dealer pursuant to the Registered Exchange Offer and (ii) an Initial
Purchaser that elects to sell Private Exchange Securities (as defined below)
acquired in exchange for Initial Securities constituting any portion of an
unsold allotment, is required to deliver a prospectus containing the information
required by Items 507 or 508 of Regulation S-K under the Securities Act, as
applicable, in connection with such sale.

     The Company shall use its commercially reasonable best efforts to keep the
Exchange Offer Registration Statement effective and to amend and supplement the
prospectus contained therein, in order to permit such prospectus to be lawfully
delivered by all persons subject to the prospectus delivery requirements of the
Securities Act for such period of time as such persons must comply with such
requirements in order to resell the Exchange Securities; provided, however, that
                                                         --------  -------
(i) in the case where such prospectus and any amendment or supplement thereto
must be delivered by an Exchanging Dealer or an Initial Purchaser, such period
shall be the lesser of 90 days after the effective date of the Registration
Statement and the date on which all Exchanging Dealers and the Initial
Purchasers have sold all Exchange Securities held by them (unless such period is
extended pursuant to Section 3(j) below) and (ii) the Company shall make such
prospectus and any amendment or supplement thereto available to any broker-
dealer for use in connection with any resale of any Exchange Securities for a
period of not less than 90 days after the effective date of the Registration
Statement.

     If, upon consummation of the Registered Exchange Offer, any Initial
Purchaser holds Initial Securities acquired by it as part of its initial
distribution, the Company, simultaneously with the delivery of the Exchange
Securities pursuant to the Registered Exchange Offer, shall issue and deliver to
such Initial Purchaser upon the written request of such Initial Purchaser, in
exchange (the "Private Exchange") for the Initial Securities held by such
Initial Purchaser, a like principal amount of debt securities of the Company
issued under the Indenture and identical in all material respects (including the
existence of restrictions on transfer under the Securities Act and the
securities laws of the several states of the United States) to the Initial
Securities (the "Private Exchange Securities").  The Initial Securities, the
Exchange Securities and the Private Exchange Securities are herein collectively
called the "Securities".

     In connection with the Registered Exchange Offer, the Company shall:

               (a)  mail to each Holder a copy of the definitive prospectus
forming part of the Exchange Offer Registration Statement, together with an
appropriate letter of transmittal and related documents;

               (b)  keep the Registered Exchange Offer open for not less than 30
days (or longer, if required by applicable law) after the date notice thereof is
mailed to the Holders;

                                      -3-
<PAGE>

               (c)  utilize the services of a depositary for the Registered
Exchange Offer with an address in the Borough of Manhattan, The City of New
York, which may be the Trustee or an affiliate of the Trustee;

               (d)  permit Holders to withdraw tendered Securities at any time
prior to the close of business, New York time, on the last business day on which
the Registered Exchange Offer shall remain open; and

               (e)  otherwise comply with all applicable laws.

     As soon as practicable after the close of the Registered Exchange Offer or
the Private Exchange, as the case may be, the Company shall:

          (x) accept for exchange all the Securities validly tendered and not
     withdrawn pursuant to the Registered Exchange Offer and the Private
     Exchange;

          (y) deliver to the Trustee for cancellation all the Initial Securities
     so accepted for exchange; and

          (z) cause the Trustee to authenticate and deliver promptly to each
     Holder of the Initial Securities, Exchange Securities or Private Exchange
     Securities, as the case may be, equal in principal amount to the Initial
     Securities of such Holder so accepted for exchange.

     The Indenture will provide that the Exchange Securities will not be subject
to the transfer restrictions set forth in the Indenture and that all the
Securities will vote and consent together on all matters as one class and that
none of the Securities will have the right to vote or consent as a class
separate from one another on any matter.

     Interest on each Exchange Security and Private Exchange Security issued
pursuant to the Registered Exchange Offer and in the Private Exchange will
accrue from the last interest payment date on which interest was paid on the
Initial Securities surrendered in exchange therefor or, if no interest has been
paid on the Initial Securities, from the date of original issue of the Initial
Securities.

     Each Holder participating in the Registered Exchange Offer shall be
required to represent to the Company in writing that at the time of the
consummation of the Registered Exchange Offer (i) any Exchange Securities
received by such Holder will be acquired in the ordinary course of business,
(ii) such Holder will have no arrangements or understanding with any person to
participate in the distribution of the Initial Securities or the Exchange
Securities within the meaning of the Securities Act, (iii) such Holder is not an
"affiliate," as defined in Rule 405 of the Securities Act, of the Company or if
it is an affiliate, such Holder will comply with the registration and prospectus
delivery requirements of the Securities Act to the extent applicable, (iv) if
such Holder is not a broker-dealer, that it is not engaged in, and does not
intend to engage in, the distribution of the Exchange Securities and (v) if such
Holder is a broker-dealer, that it will receive Exchange Securities for its own
account in exchange for Initial Securities that were acquired as a result of
market-making activities or other trading activities and that it will be

                                      -4-
<PAGE>

required to acknowledge that it will deliver a prospectus in connection with any
resale of such Exchange Securities.

     Notwithstanding any other provisions hereof, the Company will ensure that
(i) any Exchange Offer Registration Statement and any amendment thereto and any
prospectus forming a part thereof and any supplement thereto complies in all
material respects with the Securities Act and the rules and regulations
thereunder, (ii) any Exchange Offer Registration Statement and any amendment
thereto does not, when it becomes effective, contain an untrue statement of a
material fact or omit to state a material fact required to be stated therein or
necessary to make the statements therein not misleading and (iii) any prospectus
forming part of any Exchange Offer Registration Statement, and any supplement to
such prospectus, does not as of its date include an untrue statement of a
material fact or omit to state a material fact required to be stated therein or
necessary in order to make the statements therein, in the light of the
circumstances under which they were made, not misleading.

     2.   Shelf Registration.  If, (i) because of any change in law or in
applicable interpretations thereof by the staff of the Commission, the Company
is not permitted to effect a Registered Exchange Offer, as contemplated by
Section 1 hereof, (ii) the Registered Exchange Offer is not consummated by the
220th day after the Closing Date, (iii) within ten business days following
consummation of the Registered Exchange Offer any Initial Purchaser so requests
with respect to the Initial Securities (or the Private Exchange Securities) not
eligible to be exchanged for Exchange Securities in the Registered Exchange
Offer and held by it or (iv) any Holder (other than an Exchanging Dealer) of
Transfer Restricted Securities is not eligible to participate in the Registered
Exchange Offer or, in the case of any Holder (other than an Exchanging Dealer)
that participates in the Registered Exchange Offer, such Holder does not receive
freely tradeable Exchange Securities on the date of the exchange, and within ten
business days following consummation of the Registered Exchange Offer, such
Holder so requests, the Company shall take the following actions (the date on
which any of the conditions described in the foregoing clauses (i) through (iv)
occur, including in the case of clauses (iii) or (iv) the receipt of the
required notice, being a "Trigger Date"):

               (a)  The Company shall promptly (but in no event more than 120
days after the Trigger Date (such 120th day being a "Filing Deadline")) file
with the Commission and thereafter use its commercially reasonable best efforts
to cause to be declared effective no later than 180 days after the Trigger Date
(such 180th day being an "Effectiveness Deadline") a registration statement (the
"Shelf Registration Statement" and, together with the Exchange Offer
Registration Statement, a "Registration Statement") on an appropriate form under
the Securities Act relating to the offer and sale of the Transfer Restricted
Securities by the Holders thereof from time to time in accordance with the
methods of distribution set forth in the Shelf Registration Statement and Rule
415 under the Securities Act (hereinafter, the "Shelf Registration"); provided,
                                                                      --------
however, that no Holder (other than an Initial Purchaser) shall be entitled to
-------
have the Transfer Restricted Securities held by it covered by such Shelf
Registration Statement unless such Holder (i) agrees in writing to be bound by
all the provisions of this Agreement applicable to such Holder and (ii) provides
the Company in writing with the information required by Section 3(n).

                                      -5-
<PAGE>

               (b)  The Company shall use its commercially reasonable best
efforts to keep the Shelf Registration Statement continuously effective in order
to permit the prospectus included therein to be lawfully delivered by the
Holders of the relevant Securities, for a period of two years (or for such
longer period if extended pursuant to Section 3(j) below) from the date of its
effectiveness or such shorter period that will terminate when all the Securities
covered by the Shelf Registration Statement (i) have been sold pursuant thereto
or (ii) are no longer restricted securities (as defined in Rule 144 under the
Securities Act, or any successor rule thereof); provided, however, that the
Company shall not be obligated to keep the Shelf Registration Statement
continuously effective to the extent set forth above, or to keep the prospectus
included therein usable for offers and sales of Securities, if (i) the Company
determines, in its reasonable judgment, upon the advice of counsel, that the
continued effectiveness of the Shelf Registration Statement or usability of any
prospectus included therein would (x) require the disclosure of material
information, which the Company has a bona fide business reason for preserving as
confidential, or (y) interfere with any financing, acquisition, corporate
reorganization or other material transaction or development involving the
Company or any of its subsidiaries or the contemplated timing thereof, and (ii)
the Company promptly thereafter complies with the requirements of Section 3(j)
hereof, if applicable. The number of days of any actual Suspension Period (as
defined below) shall be added on to the end of the two-year period specified
above. Any such period during which the Company is excused from keeping the
Shelf Registration Statement effective and the prospectus included therein
usable for offers and sales of Securities is referred to herein as a "Suspension
Period." A Suspension Period shall commence on and include the date that the
Company gives notice that the Shelf Registration Statement is no longer
effective or the prospectus included therein is no longer usable for offers and
sales of Securities and shall end on the earlier to occur of (1) the date on
which each seller of Securities covered by the Shelf Registration Statement
either receives the copies of the supplemented or amended prospectus
contemplated by Section 3(j) hereof or is advised in writing by the Company that
the use of the prospectus may be resumed, and (2) the occurrence of a Suspension
Period Limit (as defined below). There shall be no more than three Suspension
Periods in any 12-month period, the aggregate number of days of such Suspension
Periods shall not exceed 90 days in such 12 month period (collectively, the
"Suspension Period Limits") and no Suspension Period shall exceed 60 days. The
Company shall be deemed not to have used its commercially reasonable efforts to
keep the Shelf Registration Statement effective during the requisite period if
it voluntarily takes any action that would result in Holders of Securities
covered thereby not being able to offer and sell such Securities during that
period, unless such action is required by applicable law.

               (c)  Notwithstanding any other provisions of this Agreement to
the contrary, the Company shall cause the Shelf Registration Statement and the
related prospectus and any amendment or supplement thereto, as of the effective
date of the Shelf Registration Statement, amendment or supplement, (i) to comply
in all material respects with the applicable requirements of the Securities Act
and the rules and regulations of the Commission and (ii) not to contain any
untrue statement of a material fact or omit to state a material fact required to
be stated therein or necessary in order to make the statements therein, in light
of the circumstances under which they were made, not misleading.

                                      -6-
<PAGE>

     3.   Registration Procedures.  In connection with any Shelf Registration
contemplated by Section 2 hereof and, to the extent applicable, any Registered
Exchange Offer contemplated by Section 1 hereof, the following provisions shall
apply:

               (a)  The Company shall (i) furnish to each Initial Purchaser,
prior to the filing thereof with the Commission, a copy of the Registration
Statement and each amendment thereof and each supplement, if any, to the
prospectus included therein and, in the event that an Initial Purchaser (with
respect to any portion of an unsold allotment of Initial Securities is
participating in the Registered Exchange Offer or the Shelf Registration
Statement, the Company shall use its reasonable best efforts to reflect in each
such document, when so filed with the Commission, such comments as such Initial
Purchaser reasonably may propose; (ii) include information substantially to the
effect set forth in Annex A hereto on the cover, in Annex B hereto in the
"Exchange Offer Procedures" section and the "Purpose of the Exchange Offer"
section and in Annex C hereto in the "Plan of Distribution" section of the
prospectus forming a part of the Exchange Offer Registration Statement and
include the information set forth in Annex D hereto in the Letter of Transmittal
delivered pursuant to the Registered Exchange Offer, in each case with such
changes as may be deemed reasonably appropriate by Vinson & Elkins L.L.P. as
legal counsel for the Initial Purchasers and by legal counsel for the Company;
(iii) if requested by an Initial Purchaser, include the information required by
Items 507 or 508 of Regulation S-K under the Securities Act, as applicable, in
the prospectus forming a part of the Exchange Offer Registration Statement; (iv)
include within the prospectus contained in the Exchange Offer Registration
Statement a section entitled "Plan of Distribution," reasonably acceptable to
the Initial Purchasers, which shall contain a summary statement of the positions
taken or policies made by the staff of the Commission with respect to the
potential "underwriter" status of any broker-dealer that is the beneficial owner
(as defined in Rule 13d-3 under the Securities Exchange Act of 1934, as amended
(the "Exchange Act")) of Exchange Securities received by such broker-dealer in
the Registered Exchange Offer (a "Participating Broker-Dealer"), whether such
positions or policies have been publicly disseminated by the staff of the
Commission or such positions or policies, in the reasonable judgment of the
Initial Purchasers based upon advice of counsel (which may be in-house counsel),
represent the prevailing views of the staff of the Commission; and (v) in the
case of a Shelf Registration Statement, include the names of the Holders who
propose to sell Securities pursuant to the Shelf Registration Statement as
selling securityholders.

               (b)  The Company shall give written notice to the Initial
Purchasers when the Registration Statement or any amendment thereto has been
filed with the Commission and shall give written notice to the Initial
Purchasers and (i) in the case of a Shelf Registration Statement, the Holders of
the Securities covered thereby, or (ii) in the case of an Exchange Offer
Registration Statement, the Holders of the Initial Securities and any
Participating Broker-Dealer from whom the Company has received prior written
notice that it will be a Participating Broker-Dealer in the Registered Exchange
Offer (which notice pursuant to clauses (ii)-(v) hereof shall be accompanied by
an instruction to suspend the use of the prospectus until the requisite changes
have been made):

               (i)  when the Registration Statement or any post-effective
          amendment thereto has become effective;

                                      -7-
<PAGE>

               (ii)  of any request by the Commission for amendments or
          supplements to the Registration Statement or the prospectus included
          therein or for additional information;

               (iii) of the issuance by the Commission of any stop order
          suspending the effectiveness of the Registration Statement or the
          initiation of any proceedings for that purpose;

               (iv)  of the receipt by the Company or its legal counsel of any
          notification with respect to the suspension of the qualification of
          the Securities for sale in any jurisdiction or the initiation or
          threatening of any proceeding for such purpose; and

               (v)   of the occurrence of any event, including, without
          limitation, any event resulting in a Suspension Period, that requires
          the Company to make changes in the Registration Statement or the
          prospectus in order that the Registration Statement or the prospectus
          do not contain an untrue statement of a material fact nor omit to
          state a material fact required to be stated therein or necessary to
          make the statements therein (in the case of the prospectus, in light
          of the circumstances under which they were made) not misleading.

               (c)  The Company shall make every reasonable effort to obtain the
withdrawal at the earliest possible time, of any order suspending the
effectiveness of the Registration Statement.

               (d)  The Company shall furnish to each Holder of Securities
included within the coverage of the Shelf Registration, without charge, at least
one copy of the Shelf Registration Statement and any post-effective amendment
thereto, including financial statements and schedules, and, if the Holder so
requests in writing, all exhibits thereto (including those, if any, incorporated
by reference).

               (e)  The Company shall deliver to each Exchanging Dealer and each
Initial Purchaser, and to any other Holder who so requests, without charge, at
least one copy of the Exchange Offer Registration Statement and any post-
effective amendment thereto, including financial statements and schedules, and,
if any Initial Purchaser or any such Holder requests, all exhibits thereto
(including those incorporated by reference).

               (f)  The Company shall, during the Shelf Registration Period,
deliver to each Holder of Securities included within the coverage of the Shelf
Registration, without charge, as many copies of the prospectus (including each
preliminary prospectus) included in the Shelf Registration Statement and any
amendment or supplement thereto as such person may reasonably request. The
Company consents, subject to the provisions of this Agreement, to the use of the
prospectus or any amendment or supplement thereto by each of the selling Holders
of the Securities in connection with the offering and sale of the Securities
covered by the prospectus, or any amendment or supplement thereto, included in
the Shelf Registration Statement.

                                      -8-
<PAGE>

               (g)  The Company shall deliver to each Initial Purchaser, any
Exchanging Dealer, any Participating Broker-Dealer and such other persons
required to deliver a prospectus following the Registered Exchange Offer,
without charge, as many copies of the final prospectus included in the Exchange
Offer Registration Statement and any amendment or supplement thereto as such
persons may reasonably request.  The Company consents, subject to the provisions
of this Agreement, to the use of the prospectus or any amendment or supplement
thereto by any Initial Purchaser, if necessary, any Participating Broker-Dealer
and such other persons required to deliver a prospectus following the Registered
Exchange Offer in connection with the offering and sale of the Exchange
Securities covered by the prospectus, or any amendment or supplement thereto,
included in such Exchange Offer Registration Statement.

               (h)  Prior to any public offering of the Securities pursuant to
any Registration Statement the Company shall register or qualify or cooperate
with the Holders of the Securities included therein and their respective counsel
in connection with the registration or qualification of the Securities for offer
and sale under the securities or "blue sky" laws of such states of the United
States as any Holder of the Securities reasonably requests in writing and do any
and all other acts or things necessary or advisable to enable the offer and sale
in such jurisdictions of the Securities covered by such Registration Statement;
provided, however, that the Company shall not be required to (i) qualify
--------  -------
generally to do business in any jurisdiction where it is not then so qualified
or (ii) take any action which would subject it to general service of process or
to taxation in any jurisdiction where it is not then so subject.

               (i)  The Company shall cooperate with the Holders of the
Securities to facilitate the timely transfer of the Securities to be sold
pursuant to any Registration Statement free of any restrictive legends and, to
the extent consistent with the terms of the Indenture, facilitate the timely
preparation and delivery of certificates representing the Securities in such
denominations and registered in such names as the Holders may request a
reasonable period of time prior to sales of the Securities pursuant to such
Registration Statement.

               (j)  Upon the occurrence of any event (other than an event
resulting in a Suspension Period, in which case the Company must comply with
this Section 3(j) as soon as practicable to terminate such Suspension Period)
contemplated by paragraphs (ii) through (v) of Section 3(b) above during the
period for which the Company is required to maintain an effective Registration
Statement, the Company shall promptly prepare and file a post-effective
amendment to the Registration Statement or a supplement to the related
prospectus and any other required document so that, as thereafter delivered to
Holders of the Securities or purchasers of Securities, the prospectus will not
contain an untrue statement of a material fact or omit to state any material
fact required to be stated therein or necessary to make the statements therein,
in light of the circumstances under which they were made, not misleading. If the
Company notifies the Initial Purchasers, the Holders of the Securities and any
known Participating Broker-Dealer in accordance with paragraphs (ii) through (v)
of Section 3(b) above to suspend the use of the prospectus until the requisite
changes to the prospectus have been made, then the Initial Purchasers, the
Holders of the Securities and any such Participating Broker-Dealers shall
suspend use of such prospectus, and the period of effectiveness of the Shelf
Registration Statement provided for in Section 2(b) above and the Exchange Offer
Registration Statement provided for in Section 1 above shall each be extended by
the number of days, without duplication of any

                                      -9-
<PAGE>

extension under Section 2(b), from and including the date of the giving of such
notice to and including the date when the Initial Purchasers, the Holders of the
Securities and any known Participating Broker-Dealer, as applicable, shall have
received such amended or supplemented prospectus pursuant to this Section 3(j)
or the date when none of the Securities represent Transfer Restricted
Securities.

               (k)  Not later than the effective date of the applicable
Registration Statement, the Company will provide a CUSIP number for the Initial
Securities, the Exchange Securities or the Private Exchange Securities, as the
case may be, and provide the applicable trustee with printed certificates for
the Initial Securities, the Exchange Securities or the Private Exchange
Securities, as the case may be, in a form eligible for deposit with The
Depository Trust Company.

               (l)  The Company will comply with all rules and regulations of
the Commission to the extent and so long as they are applicable to the
Registered Exchange Offer or the Shelf Registration and will make generally
available to its security holders (or otherwise provide in accordance with
Section 11(a) of the Securities Act) an earnings statement satisfying the
provisions of Section 11(a) of the Securities Act, no later than 45 days after
the end of a 12-month period (or 90 days, if such period is a fiscal year)
beginning with the first month of the Company's first fiscal quarter commencing
after the effective date of the Registration Statement, which statement shall
cover such 12-month period.

               (m)  The Company shall cause the Indenture to be qualified under
the Trust Indenture Act of 1939, as amended, in a timely manner and containing
such changes, if any, as shall be necessary for such qualification. In the event
that such qualification would require the appointment of a new trustee under the
Indenture, the Company shall appoint a new trustee thereunder pursuant to the
applicable provisions of the Indenture.

               (n)  The Company may require each Holder of Securities to be sold
pursuant to the Shelf Registration Statement to furnish to the Company such
information regarding the Holder and the distribution of the Securities as the
Company may from time to time reasonably require for inclusion in the Shelf
Registration Statement, and the Company may exclude from such registration the
Securities of any Holder that unreasonably fails to furnish such information
within a reasonable time after receiving such request.  The Company may require
each Holder as to which a Shelf Registration Statement is effected to furnish,
update or confirm promptly to the Company information regarding the Holder and
the distribution of Securities required to be disclosed in order to make the
information previously furnished to the Company by such Holder not materially
misleading.

               (o)  The Company shall enter into such customary agreements
(including, if requested, an underwriting agreement in customary form) and take
all such other action, if any, as any Holder of the Securities shall reasonably
request in order to facilitate the disposition of the Securities pursuant to any
Shelf Registration.

               (p)  In the case of any Shelf Registration, the Company shall (i)
upon reasonable notice and during normal business hours, make reasonably
available for inspection by

                                      -10-
<PAGE>

the Holders of the Securities, any underwriter participating in any disposition
pursuant to the Shelf Registration Statement and any attorney, accountant or
other agent retained by the Holders of the Securities or any such underwriter
all relevant financial and other records, pertinent corporate documents and
properties of the Company and (ii) use its reasonable best efforts to cause the
Company's officers, directors, employees, accountants and auditors to supply all
relevant information reasonably requested by the Holders of the Securities or
any such underwriter, attorney, accountant or agent in connection with the Shelf
Registration Statement, in each case, as shall be reasonably necessary to enable
such persons, to conduct a reasonable investigation within the meaning of
Section 11 of the Securities Act; provided, however, that information that is
                                  --------  -------
designated in writing by the Company in good faith as confidential at the time
of delivery of such information shall be kept confidential by such Holder or any
such underwriter, attorney, accountant or agent, unless such disclosure is made
in the public generally or through a third party without an accompanying
obligation of confidentiality; and provided, further, the foregoing inspection
and information gathering shall be coordinated on behalf of the Initial
Purchasers by you and on behalf of the other parties, by one counsel designated
by and on behalf of such other parties as described in Section 4 hereof.

               (q)  In the case of any Shelf Registration, the Company, if
requested by any Holder of Securities covered thereby, shall cause (i) its
counsel to deliver an opinion and updates thereof relating to the Securities in
customary form addressed to such Holders and the managing underwriters, if any,
thereof and dated, in the case of the initial opinion, the effective date of
such Shelf Registration Statement (it being agreed that the matters to be
covered by such opinion shall include, without limitation, the due incorporation
or organization and good standing of the Company and its subsidiaries; the
qualification of the Company and its subsidiaries to transact business as
foreign corporations; the due authorization, execution and delivery of the
relevant agreement of the type referred to in Section 3(o) hereof; the due
authorization, execution, authentication and issuance, and the validity and
enforceability, of the applicable Securities; the absence of material legal or
governmental proceedings involving the Company and its subsidiaries; the absence
of governmental approvals required to be obtained in connection with the Shelf
Registration Statement, the offering and sale of the applicable Securities, or
any agreement of the type referred to in Section 3(o) hereof; the compliance as
to form of such Shelf Registration Statement and any documents incorporated by
reference therein and of the Indenture with the requirements of the Securities
Act and the Trust Indenture Act, respectively; and, as of the date of the
opinion and as of the effective date of the Shelf Registration Statement or most
recent post-effective amendment thereto, as the case may be, the absence from
such Shelf Registration Statement and the prospectus included therein, as then
amended or supplemented, and from any documents incorporated by reference
therein of an untrue statement of a material fact or the omission to state
therein a material fact required to be stated therein or necessary to make the
statements therein not misleading (in the case of any such documents, in the
light of the circumstances existing at the time that such documents were filed
with the Commission under the Exchange Act); (ii) its officers to execute and
deliver all customary documents and certificates and updates thereof reasonably
requested by any underwriters of the applicable Securities and (iii) its
independent public accountants and the independent public accountants with
respect to any other entity for which financial information is provided in the
Shelf Registration Statement to provide to the selling Holders of the applicable

                                      -11-
<PAGE>

Securities and any underwriter therefor a comfort letter in customary form and
covering matters of the type customarily covered in comfort letters in
connection with primary underwritten offerings, subject to receipt of
appropriate documentation as contemplated, and only if permitted, by Statement
of Auditing Standards No. 72.

               (r)  In the case of the Registered Exchange Offer, if requested
by any Initial Purchaser or any known Participating Broker-Dealer, the Company
shall cause (i) its counsel to deliver to such Initial Purchaser or such
Participating Broker-Dealer a signed opinion in the form set forth in Section
6(f) of the Purchase Agreement with such changes as are customary in connection
with the preparation of a Registration Statement and (ii) its independent public
accountants and the independent public accountants with respect to any other
entity for which financial information is provided in the Registration Statement
to deliver to such Initial Purchaser or such Participating Broker-Dealer a
comfort letter, in customary form, meeting the requirements as to the substance
thereof as set forth in Section 6(a) - (c) of the Purchase Agreement, with
appropriate date changes.

               (s)  If a Registered Exchange Offer or a Private Exchange is to
be consummated, upon delivery of the Initial Securities by Holders to the
Company (or to such other Person as directed by the Company) in exchange for the
Exchange Securities or the Private Exchange Securities, as the case may be, the
Company shall mark, or caused to be marked, on the Initial Securities so
exchanged that such Initial Securities are being canceled in exchange for the
Exchange Securities or the Private Exchange Securities, as the case may be; in
no event shall the Initial Securities be marked as paid or otherwise satisfied.

               (t)  The Company will use its reasonable best efforts to (a) if
the Initial Securities have been rated prior to the initial sale of such Initial
Securities, confirm such ratings will apply to the Securities covered by a
Registration Statement, or (b) if the Initial Securities were not previously
rated, cause the Securities covered by a Registration Statement to be rated with
the appropriate rating agencies, if so requested by Holders of a majority in
aggregate principal amount of Securities covered by such Registration Statement,
or by the managing underwriters, if any.

               (u)  In the event that any broker-dealer registered under the
Exchange Act shall underwrite any Securities to be sold pursuant to the Shelf
Registration Statement or participate as a member of an underwriting syndicate
or selling group or "assist in the distribution" (within the meaning of the
Conduct Rules (the "Rules") of the National Association of Securities Dealers,
Inc. ("NASD")) thereof, whether as a Holder of such Securities or as an
underwriter, a placement or sales agent or a broker or dealer in respect
thereof, or otherwise, the Company will assist such broker-dealer in complying
with the requirements of such Rules, including, without limitation, by (i) if
such Rules, including Rule 2720, shall so require, engaging a "qualified
independent underwriter" (as defined in Rule 2720) to participate in the
preparation of the Registration Statement relating to such Securities, to
exercise usual standards of due diligence in respect thereto and, if any portion
of the offering contemplated by such Registration Statement is an underwritten
offering or is made through a placement or sales agent, to recommend the yield
of such Securities, (ii) indemnifying any such qualified independent underwriter
to the extent of the indemnification of underwriters provided in Section 5
hereof and

                                      -12-
<PAGE>

(iii) providing such information to such broker-dealer as may be required in
order for such broker-dealer to comply with the requirements of the Rules.

               (v)   The Company shall use its reasonable best efforts to take
all other steps necessary to effect the registration of the Securities covered
by a Registration Statement contemplated hereby.

     4.   Registration Expenses. (a) All expenses incident to the Company's
performance of and compliance with this Agreement will be borne by the Company,
regardless of whether a Registration Statement is ever filed or becomes
effective, including without limitation;

               (i)   all registration and filing fees and expenses;

               (ii)  all fees and expenses of compliance with federal securities
          and state "blue sky" or securities laws;

               (iii) all expenses of printing (including printing certificates
          for the Securities to be issued in the Registered Exchange Offer and
          the Private Exchange and printing of prospectuses), messenger and
          delivery services and telephone;

               (iv)  all fees and disbursements of counsel for the Company;

               (v)   all application and filing fees in connection with listing
          the Exchange Securities on a national securities exchange or automated
          quotation system pursuant to the requirements hereof; and

               (vi)  all fees and disbursements of independent certified public
          accountants of the Company (including the expenses of any special
          audit and comfort letters required by or incident to such
          performance).

The Company will bear its internal expenses (including, without limitation, all
salaries and expenses of its officers and employees performing legal or
accounting duties), the expenses of any annual audit and the fees and expenses
of any person, including special experts, retained by the Company.

               (b)   In connection with any Registration Statement required by
this Agreement, the Company will reimburse the Initial Purchasers and the
Holders of Transfer Restricted Securities who are tendering Initial Securities
in the Registered Exchange Offer and/or selling or reselling Securities pursuant
to the "Plan of Distribution" contained in the Exchange Offer Registration
Statement or the Shelf Registration Statement, as applicable, for the reasonable
fees and disbursements (which fees and disbursements shall be limited to
$10,000) of not more than one counsel, who shall be Vinson & Elkins L.L.P.,
Houston, Texas, unless another firm shall be chosen by the Holders of a majority
in principal amount of the Transfer Restricted Securities for whose benefit such
Registration Statement is being prepared.

     5.   Indemnification. (a) The Issuer and the Guarantors will, jointly and
severally, indemnify and hold harmless each Holder of the Securities, any
Participating Broker-Dealer and

                                      -13-
<PAGE>

each person, if any, who controls such Holder or such Participating Broker-
Dealer within the meaning of the Securities Act or the Exchange Act (each
Holder, any Participating Broker-Dealer and such controlling persons are
referred to collectively as the "Indemnified Parties") from and against any
losses, claims, damages or liabilities, joint or several, or any actions in
respect thereof (including, but not limited to, any losses, claims, damages,
liabilities or actions relating to purchases and sales of the Securities) to
which each Indemnified Party may become subject under the Securities Act, the
Exchange Act or otherwise, insofar as such losses, claims, damages, liabilities
or actions arise out of or are based upon any untrue statement or alleged untrue
statement of a material fact contained in a Registration Statement or prospectus
or in any amendment or supplement thereto or in any preliminary prospectus
relating to a Shelf Registration, or arise out of, or are based upon, the
omission or alleged omission to state therein a material fact required to be
stated therein or necessary to make the statements therein, in the light of the
circumstances under which they were made, not misleading, and shall reimburse,
as incurred, the Indemnified Parties for any legal or other expenses reasonably
incurred by them in connection with investigating or defending any such loss,
claim, damage, liability or action in respect thereof; provided, however, that
                                                       --------  -------
(i) the Company shall not be liable in any such case to the extent that such
loss, claim, damage or liability or action arises out of or is based upon any
untrue statement or alleged untrue statement or omission or alleged omission
made in a Registration Statement or prospectus or in any amendment or supplement
thereto or in any preliminary prospectus relating to a Shelf Registration in
reliance upon and in conformity with written information pertaining to such
Holder and furnished to the Company by or on behalf of such Indemnified Party or
affiliate thereof specifically for inclusion therein and (ii) with respect to
any untrue statement or omission or alleged untrue statement or omission made in
any preliminary prospectus relating to a Shelf Registration Statement, the
indemnity agreement contained in this subsection (a) shall not inure to the
benefit of any Holder or Participating Broker-Dealer from whom the person
asserting any such losses, claims, damages or liabilities purchased the
Securities concerned, to the extent that a prospectus relating to such
Securities was required to be delivered by such Holder or Participating Broker-
Dealer under the Securities Act in connection with such purchase and any such
loss, claim, damage or liability of such Holder or Participating Broker-Dealer
results from the fact that there was not sent or given to such person, at or
prior to the written confirmation of the sale of such Securities to such person,
a copy of the final prospectus if the Company had previously furnished copies
thereof to such Holder or Participating Broker-Dealer; provided further,
                                                       -------- -------
however, that this indemnity agreement will be in addition to any liability
-------
which the Company may otherwise have to such Indemnified Party. The Company
shall also indemnify underwriters, their officers and directors and each person
who controls such underwriters within the meaning of the Securities Act or the
Exchange Act to the same extent as provided above with respect to the
indemnification of the Holders of the Securities if requested by such Holders.

               (b)  Each Holder of the Securities, severally and not jointly,
will indemnify and hold harmless the Company and each person, if any, who
controls the Company within the meaning of the Securities Act or the Exchange
Act from and against any losses, claims, damages or liabilities or any actions
in respect thereof, to which the Company or any such controlling person may
become subject under the Securities Act, the Exchange Act or otherwise, insofar
as such losses, claims, damages, liabilities or actions arise out of or are
based

                                      -14-
<PAGE>

upon any untrue statement or alleged untrue statement of a material fact
contained in a Registration Statement or prospectus or in any amendment or
supplement thereto or in any preliminary prospectus relating to a Shelf
Registration, or arise out of or are based upon the omission or alleged omission
to state therein a material fact necessary to make the statements therein, in
light of the circumstances under which they were made, not misleading, but in
each case only to the extent that the untrue statement or omission or alleged
untrue statement or omission was made in reliance upon and in conformity with
written information pertaining to such Holder and furnished to the Company by or
on behalf of such Holder specifically for inclusion therein; and, subject to the
limitation set forth immediately preceding this clause, shall reimburse, as
incurred, the Company for any legal or other expenses reasonably incurred by the
Company or any such controlling person in connection with investigating or
defending any loss, claim, damage, liability or action in respect thereof. This
indemnity agreement will be in addition to any liability which such Holder may
otherwise have to the Company or any of its controlling persons.

          (c)  Promptly after receipt by an indemnified party under this Section
5 of notice of the commencement of any action or proceeding (including a
governmental investigation), such indemnified party will, if a claim in respect
thereof is to be made against the indemnifying party under this Section 5,
notify the indemnifying party in writing of the commencement thereof; but the
omission so to notify the indemnifying party will not, in any event, relieve the
indemnifying party from any obligations to any indemnified party other than the
indemnification obligation provided in paragraph (a) or (b) above.  In case any
such action is brought against any indemnified party, and it notifies the
indemnifying party of the commencement thereof, the indemnifying party will be
entitled to participate therein and, to the extent that it may wish, jointly
with any other indemnifying party similarly notified, to assume the defense
thereof, with counsel reasonably satisfactory to such indemnified party (who
shall not, except with the consent of the indemnified party, be counsel to the
indemnifying party), and after notice from the indemnifying party to such
indemnified party of its election so to assume the defense thereof the
indemnifying party will not be liable to such indemnified party under this
Section 5 for any legal or other expenses, other than reasonable costs of
investigation, subsequently incurred by such indemnified party in connection
with the defense thereof.  No indemnifying party shall, without the prior
written consent of the indemnified party, effect any settlement of any pending
or threatened action in respect of which any indemnified party is or could have
been a party and indemnity could have been sought hereunder by such indemnified
party unless such settlement includes an unconditional release of such
indemnified party from all liability on any claims that are the subject matter
of such action, and does not include a statement as to or an admission of fault,
culpability or a failure to act by or on behalf of any indemnified party.

          (d)  If the indemnification provided for in this Section 5 is
unavailable or insufficient to hold harmless an indemnified party under
subsections (a) or (b) above, then each indemnifying party shall contribute to
the amount paid or payable by such indemnified party as a result of the losses,
claims, damages or liabilities (or actions in respect thereof) referred to in
subsection (a) or (b) above (i) in such proportion as is appropriate to reflect
the relative benefits received by the indemnifying party or parties on the one
hand and the indemnified party on the

                                      -15-
<PAGE>

other from the exchange of the Securities, pursuant to the applicable
Registration Statement or prospectus, or (ii) if the allocation provided by the
foregoing clause (i) is not permitted by applicable law, in such proportion as
is appropriate to reflect not only the relative benefits referred to in clause
(i) above but also the relative fault of the indemnifying party or parties on
the one hand and the indemnified party on the other in connection with the
statements or omissions that resulted in such losses, claims, damages or
liabilities (or actions in respect thereof) as well as any other relevant
equitable considerations. The relative fault of the parties shall be determined
by reference to, among other things, whether the untrue or alleged untrue
statement of a material fact or the omission or alleged omission to state a
material fact relates to information supplied by the Company on the one hand or
such Holder or such other indemnified party, as the case may be, on the other,
and the parties' relative intent, knowledge, access to information and
opportunity to correct or prevent such statement or omission. The amount paid by
an indemnified party as a result of the losses, claims, damages or liabilities
referred to in the first sentence of this subsection (d) shall be deemed to
include any legal or other expenses reasonably incurred by such indemnified
party in connection with investigating or defending any action or claim which is
the subject of this subsection (d). Notwithstanding any other provision of this
Section 5(d), the Holders of the Securities shall not be required to contribute
any amount in excess of the amount by which the net proceeds received by such
Holders from the sale of the Securities pursuant to a Registration Statement
exceeds the amount of damages which such Holders have otherwise been required to
pay by reason of such untrue or alleged untrue statement or omission or alleged
omission. No person guilty of fraudulent misrepresentation (within the meaning
of Section 11(f) of the Securities Act) shall be entitled to contribution from
any person who was not guilty of such fraudulent misrepresentation. For purposes
of this paragraph (d), each person, if any, who controls such indemnified party
within the meaning of the Securities Act or the Exchange Act shall have the same
rights to contribution as such indemnified party and each person, if any, who
controls the Company within the meaning of the Securities Act or the Exchange
Act shall have the same rights to contribution as the Company.

               (e)  The agreements contained in this Section 5 shall survive the
sale of the Securities pursuant to a Registration Statement and shall remain in
full force and effect, regardless of any termination or cancellation of this
Agreement or any investigation made by or on behalf of any indemnified party.

     6.   Additional Interest Under Certain Circumstances. (a) Additional
interest (the "Additional Interest") with respect to the Initial Securities and
the Private Exchange Securities shall be assessed as follows if any of the
following events occur (each such event in clauses (i) through (iv) below being
herein called a "Registration Default"):

               (i)   any Registration Statement required by this Agreement is
          not filed with the Commission on or prior to the applicable Filing
          Deadline;

               (ii)  any Registration Statement required by this Agreement is
          not declared effective by the Commission on or prior to the applicable
          Effectiveness Deadline;

                                      -16-
<PAGE>

               (iii) the Registered Exchange Offer has not been consummated on
          or prior to the Consummation Deadline; or

               (iv)  any Registration Statement required by this Agreement has
          been declared effective by the Commission but (A) such Registration
          Statement thereafter ceases to be effective or (B) such Registration
          Statement or the related prospectus ceases to be usable in connection
          with resales of Transfer Restricted Securities during the periods
          specified herein because either (1) any event occurs as a result of
          which the related prospectus forming part of such Registration
          Statement would include any untrue statement of a material fact or
          omit to state any material fact necessary to make the statements
          therein in the light of the circumstances under which they were made
          not misleading, or (2) it shall be necessary to amend such
          Registration Statement or supplement the related prospectus, to comply
          with the Securities Act or the Exchange Act or the respective rules
          thereunder.

Each of the foregoing will constitute a Registration Default whatever the reason
for any such event and whether it is voluntary or involuntary or is beyond the
control of the Company or pursuant to operation of law or as a result of any
action or inaction by the Commission.

     Additional Interest shall accrue on the Initial Securities and the Private
Exchange Securities over and above the interest set forth in the title of the
Securities from and including the date on which any such Registration Default
shall occur to but excluding the date on which all such Registration Defaults
have been cured, at a rate (the "Additional Interest Rate") of 0.25% per annum
for the first 90-day period immediately following the occurrence of such
Registration Default. The Additional Interest Rate shall increase to 0.50% per
annum subsequent to the first 90-day period until all Registration Defaults have
been cured.

          (b)  A Registration Default referred to in Section 6(a)(iv) hereof
shall be deemed not to have occurred and be continuing in relation to a Shelf
Registration Statement or the related prospectus if (i) such Registration
Default has occurred solely as a result of (x) the filing of a post-effective
amendment to such Shelf Registration Statement to incorporate annual audited
financial information with respect to the Company where such post-effective
amendment is not yet effective and needs to be declared effective to permit
Holders to use the related prospectus or (y) other material events, with respect
to the Company that would need to be described in such Shelf Registration
Statement or the related prospectus and (ii) in the case of clause (y), the
Company is proceeding promptly and in good faith to amend or supplement such
Shelf Registration Statement and related prospectus to describe such events;
provided, however, that in any case if such Registration Default occurs for a
--------  -------
continuous period in excess of 30 days, Additional Interest shall be payable in
accordance with the above paragraph from the day such Registration Default
occurs until such Registration Default is cured.

          (c)  Any amounts of Additional Interest due pursuant to Section 6(a)
will be payable in cash on the regular interest payment dates with respect to
the Securities. The amount of Additional Interest will be determined by
multiplying the applicable Additional Interest Rate by the principal amount of
the Initial Securities or Private Exchange Securities, as

                                      -17-
<PAGE>

the case may be, and further multiplied by a fraction, the numerator of which is
the number of days such Additional Interest Rate was applicable during such
period (determined on the basis of a 360-day year comprised of twelve 30-day
months), and the denominator of which is 360.

               (d)  "Transfer Restricted Securities" means each Security until
(i) the date on which such Security has been exchanged by a person other than a
broker-dealer for a freely transferable Exchange Security in the Registered
Exchange Offer, (ii) following the exchange by a broker-dealer in the Registered
Exchange Offer of an Initial Security for an Exchange Security, the date on
which such Exchange Security is sold to a purchaser who receives from such
broker-dealer on or prior to the date of such sale a copy of the prospectus
contained in the Exchange Offer Registration Statement, (iii) the date on which
such Security has been effectively registered under the Securities Act and
disposed of in accordance with the Shelf Registration Statement or (iv) the date
on which such Security is distributed to the public pursuant to Rule 144 under
the Securities Act or is saleable pursuant to Rule 144(k) under the Securities
Act.

     7.   Rules 144 and 144A. The Company shall use its reasonable best efforts
to file the reports required to be filed by it under the Securities Act and the
Exchange Act in a timely manner and, if at any time the Company is not required
to file such reports, it will, upon the request of any Holder of Transfer
Restricted Securities, make publicly available other information so long as
necessary to permit sales of their Transfer Restricted Securities pursuant to
Rules 144 and 144A. The Company covenants that it will take such further action
as any Holder of Transfer Restricted Securities may reasonably request, all to
the extent required from time to time to enable such Holder to sell Transfer
Restricted Securities without registration under the Securities Act within the
limitation of the exemptions provided by Rules 144 and 144A (including the
requirements of Rule 144A(d)(4)). The Company will provide a copy of this
Agreement to prospective purchasers of Initial Securities identified to the
Company by the Initial Purchasers upon request. Upon the request of any Holder
of Initial Securities, the Company shall deliver to such Holder a written
statement as to whether it has complied with such requirements. Notwithstanding
the foregoing, nothing in this Section 7 shall be deemed to require the Company
to register any of its securities pursuant to the Exchange Act.

     8.   Underwritten Registrations.  If any of the Transfer Restricted
Securities covered by any Shelf Registration are to be sold in an underwritten
offering, the investment banker or investment bankers and manager or managers
that will administer the offering ("Managing Underwriters") will be selected by
the Holders of a majority in aggregate principal amount of such Transfer
Restricted Securities to be included in such offering (subject to the approval,
which approval shall not be unreasonably withheld, of the Issuer).

     No person may participate in any underwritten registration hereunder unless
such person (i) agrees to sell such person's Transfer Restricted Securities on
the basis reasonably provided in any underwriting arrangements approved by the
persons entitled hereunder to approve such arrangements and (ii) completes and
executes all questionnaires, powers of attorney, indemnities, underwriting
agreements and other documents reasonably required under the terms of such
underwriting arrangements.

                                      -18-
<PAGE>

     9.   Miscellaneous.

          (a)  Remedies. The Company acknowledges and agrees that any failure by
     the Company to comply with its obligations under Section 1 and 2 hereof may
     result in material irreparable injury to the Initial Purchasers or the
     Holders for which there is no adequate remedy at law, that it will not be
     possible to measure damages for such injuries precisely and that, in the
     event of any such failure, the Initial Purchasers or any Holder may obtain
     such relief as may be required to specifically enforce the Company's
     obligations under Sections 1 and 2 hereof. The Company further agrees to
     waive the defense in any action for specific performance that a remedy at
     law would be adequate.

          (b)  No Inconsistent Agreements. The Company will not on or after the
     date of this Agreement enter into any agreement with respect to its
     securities that is inconsistent with the rights granted to the Holders in
     this Agreement or otherwise conflicts with the provisions hereof. The
     rights granted to the Holders hereunder do not in any way conflict with and
     are not inconsistent with the rights granted to the holders of the
     Company's securities under any agreement in effect on the date hereof.

          (c)  Amendments and Waivers. The provisions of this Agreement may not
     be amended, modified or supplemented, and waivers or consents to departures
     from the provisions hereof may not be given, except by the Company and the
     written consent of the Holders of a majority in principal amount of the
     Securities affected by such amendment, modification, supplement, waiver or
     consents.

          (d)  Notices. All notices and other communications provided for or
     permitted hereunder shall be made in writing by hand delivery, first-class
     mail, facsimile transmission, or air courier which guarantees overnight
     delivery:

               (1)  if to a Holder of the Securities, at the most current
     address given by such Holder to the Company.

               (2)  if to the Initial Purchasers;

                       Credit Suisse First Boston Corporation
                       Eleven Madison Avenue
                       New York, NY 10010-3629
                       Fax No.: (212) 325-8278
                       Attention: Transactions Advisory Group

               with a copy to:

                       Vinson & Elkins L.L.P.
                       2300 First City Tower
                       1001 Fannin
                       Houston, Texas 77002-6760
                       Fax No.: (713) 615-5282

                                      -19-
<PAGE>

                       Attention: Michael P. Finch

               (3)  if to the Company, at its address as follows:

                       Pure Resources, Inc.
                       500 West Illinois
                       Midland, Texas 79701
                       Fax No.: (915) 687-3863
                       Attention: Jack Hightower

               with a copy to:

                       Thompson & Knight L.L.P.
                       1700 Pacific Avenue, Suite 3300
                       Dallas, Texas 75201-4693
                       Fax No.: (214) 969-1751
                       Attention: Joe Dannenmaier

     All such notices and communications shall be deemed to have been duly
given: at the time delivered by hand, if personally delivered; three business
days after being deposited in the mail, postage prepaid, if mailed; when receipt
is acknowledged by recipient's facsimile machine operator, if sent by facsimile
transmission; and on the day delivered, if sent by overnight air courier
guaranteeing next day delivery.

               (e)     Third Party Beneficiaries. The Holders shall be third
party beneficiaries to the agreements made hereunder between the Company, on the
one hand, and the Initial Purchasers, on the other hand, and shall have the
right to enforce such agreements directly to the extent they may deem such
enforcement necessary or advisable to protect their rights or the rights of
Holders hereunder.

               (f)     Successors and Assigns. This Agreement shall be binding
upon the Company and its successors and assigns.

               (g)     Counterparts. This Agreement may be executed in any
number of counterparts and by the parties hereto in separate counterparts, each
of which when so executed shall be deemed to be an original and all of which
taken together shall constitute one and the same agreement.

               (h)     Headings. The headings in this Agreement are for
convenience of reference only and shall not limit or otherwise affect the
meaning hereof.

               (i)     Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY, AND
CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK WITHOUT REGARD
TO PRINCIPLES OF CONFLICTS OF LAWS.

                                      -20-
<PAGE>

          (j)  Severability. If any one or more of the provisions contained
herein, or the application thereof in any circumstance, is held invalid, illegal
or unenforceable, the validity, legality and enforceability of any such
provision in every other respect and of the remaining provisions contained
herein shall not be affected or impaired thereby.

          (k)  Securities Held by the Company. Whenever the consent or approval
of Holders of a specified percentage of principal amount of Securities is
required hereunder, Securities held by the Company or its affiliates (other than
subsequent Holders of Securities if such subsequent Holders are deemed to be
affiliates solely by reason of their holdings of such Securities) shall not be
counted in determining whether such consent or approval was given by the Holders
of such required percentage.

                                      -21-
<PAGE>

     If the foregoing is in accordance with your understanding of our agreement,
please sign and return to the Company a counterpart hereof, whereupon this
instrument, along with all counterparts, will become a binding agreement among
the several Initial Purchasers, the Company and the Guarantors in accordance
with its terms.

                              Very truly yours,

                              PURE RESOURCES, INC.
                              TITAN EXPLORATION, INC.
                              PURE RESOURCES I, INC.
                              HALLWOOD PETROLEUM, INC.
                              PURE GP, LLC
                              HEP PURE ACQUISITION, LLC


                              By:  /s/ William White
                                 ----------------------------------------------
                              Name:  William K. White
                              Title:  Vice President



                              PURE RESOURCES HOLDINGS, INC.
                              PURE RESOURCES HOLDINGS, LLC


                              By:  /s/ Richard Klumpp
                                 ----------------------------------------------
                              Name:  Richard Klumpp
                              Title:  Vice President

                              PURE RESOURCES, L.P.
                              PK I, L.P.
                              PK II, L.P.
                              PK III, L.P.
                              PK IV, L.P.


                              By:  PURE RESOURCES I, INC., its general partner

                                   By:  /s/ William White
                                      -----------------------------------------
                                   Name:  William K. White
                                   Title:  Vice President

                                      -22-
<PAGE>

                                      HEP PURE, LP

                                      By:  PURE GP, LLC, its general partner


                                           By:  /s/ William White
                                                --------------------------------
                                           Name:  William K. White
                                           Title:  Vice President


                                           HALLWOOD ENERGY PARTNERS, L.P.



                                      By:  HEP PURE ACQUISITION, LLC,
                                           its general partner


                                           By:  /s/ William White
                                                --------------------------------
                                           Name:  William K. White
                                           Title:  Vice President


                                      LA PLATA ASSOCIATES, LLC
                                      HALLWOOD LA PLATA, LLC


                                      By:  HALLWOOD PETROLEUM, INC.
                                           its manager


                                           By:  /s/ William White
                                                --------------------------------
                                           Name:  William K. White
                                           Title:  Vice President

                                      -23-
<PAGE>

The foregoing Registration
Rights Agreement is hereby confirmed
and accepted as of the date first
above written.

Credit Suisse First Boston Corporation
First Union Securities, Inc.
BNP Paribas Securities Corp.
Fleet Securities, Inc.
Credit Lyonnais Securities (USA) Inc.
BNY Capital Markets, Inc.
Wells Fargo Brokerage Services, LLC

By:  Credit Suisse First Boston Corporation


By:  /s/ Timothy Perry
     ----------------------------
Name:  Timothy Perry
Title:  Director

                                      -24-
<PAGE>

                                                                         ANNEX A


          Each broker-dealer that receives Exchange Securities for its own
account pursuant to the Exchange Offer must acknowledge that it will deliver a
prospectus in connection with any resale of such Exchange Securities.  The
Letter of Transmittal states that by so acknowledging and by delivering a
prospectus, a broker-dealer will not be deemed to admit that it is an
"underwriter" within the meaning of the Securities Act.  This Prospectus, as it
may be amended or supplemented from time to time, may be used by a broker-dealer
in connection with resales of Exchange Securities received in exchange for
Initial Securities where such Initial Securities were acquired by such broker-
dealer as a result of market-making activities or other trading activities.  The
Company has agreed that, until ___________, 2001 [90 days after the effective
date of the Registration Statement], it will make this Prospectus available to
any broker-dealer for use in connection with any such resale.  See "Plan of
Distribution."

                                      -25-
<PAGE>

                                                                         ANNEX B


          Each broker-dealer that receives Exchange Securities for its own
account in exchange for Initial Securities, where such Initial Securities were
acquired by such broker-dealer as a result of market-making activities or other
trading activities, must acknowledge that it will deliver a prospectus in
connection with any resale of such Exchange Securities. See "Plan of
Distribution."

                                      -26-
<PAGE>

                                                                         ANNEX C


                              PLAN OF DISTRIBUTION

     Each broker-dealer that receives Exchange Securities for its own account
pursuant to the Exchange Offer must acknowledge that it will deliver a
prospectus in connection with any resale of such Exchange Securities. This
Prospectus, as it may be amended or supplemented from time to time, may be used
by a broker-dealer in connection with resales of Exchange Securities received in
exchange for Initial Securities where such Initial Securities were acquired as a
result of market-making activities or other trading activities. The Company has
agreed that, until ___________, 2001 [90 days after the effective date of the
Registration Statement], it will make this prospectus, as amended or
supplemented, available to any broker-dealer for use in connection with any such
resale. In addition, until ________, 2001, all dealers effecting transactions in
the Exchange Securities may be required to deliver a prospectus.

     The Company will not receive any proceeds from any sale of Exchange
Securities by broker-dealers. Exchange Securities received by broker-dealers for
their own account pursuant to the Exchange Offer may be sold from time to time
in one or more transactions in the over-the-counter market, in negotiated
transactions, through the writing of options on the Exchange Securities or a
combination of such methods of resale, at market prices prevailing at the time
of resale, at prices related to such prevailing market prices or negotiated
prices. Any such resale may be made directly to purchasers or to or through
brokers or dealers who may receive compensation in the form of commissions or
concessions from any such broker-dealer or the purchasers of any such Exchange
Securities. Any broker-dealer that resells Exchange Securities that were
received by it for its own account pursuant to the Exchange Offer and any broker
or dealer that participates in a distribution of such Exchange Securities may be
deemed to be an "underwriter" within the meaning of the Securities Act and any
profit on any such resale of Exchange Securities and any commission or
concessions received by any such persons may be deemed to be underwriting
compensation under the Securities Act. The Letter of Transmittal states that, by
acknowledging that it will deliver and by delivering a prospectus, a broker-
dealer will not be deemed to admit that it is an "underwriter" within the
meaning of the Securities Act.

     Until ___________, 2001 [90 days after the effective date of the
Registration Statement], the Company will promptly send additional copies of
this Prospectus and any amendment or supplement to this Prospectus to any
broker-dealer that requests such documents in the Letter of Transmittal. The
Company has agreed to pay all expenses incident to the Exchange Offer (including
the expenses of one counsel for the Holders of the Securities) other than
commissions or concessions of any brokers or dealers and will indemnify the
Holders of the Securities (including any broker-dealers) against certain
liabilities, including liabilities under the Securities Act.

                                      -27-
<PAGE>

                                                                         ANNEX D


     [_]  CHECK HERE IF YOU ARE A BROKER-DEALER AND WISH TO RECEIVE 10
ADDITIONAL COPIES OF THE PROSPECTUS AND 10 COPIES OF ANY AMENDMENTS OR
SUPPLEMENTS THERETO.

     Name:____________________________

     Address:_________________________


     If the undersigned is not a broker-dealer, the undersigned represents that
it is not engaged in, and does not intend to engage in, a distribution of
Exchange Securities. If the undersigned is a broker-dealer that will receive
Exchange Securities for its own account in exchange for Initial Securities that
were acquired as a result of market-making activities or other trading
activities, it acknowledges that it will deliver a prospectus in connection with
any resale of such Exchange Securities; however, by so acknowledging and by
delivering a prospectus, the undersigned will not be deemed to admit that it is
an "underwriter" within the meaning of the Securities Act.

                                      -28-