<PAGE>
                                                                     EXHIBIT 4.2


                          REGISTRATION RIGHTS AGREEMENT

                           Dated as of March 31, 2004

                                 By and Between

                                GREY WOLF, INC.,
                                 as the Company,


                                       and


                               D/I PERFENSA INC.,

                                DI ENERGY, INC.,

                        GREY WOLF DRILLING COMPANY L.P.,

                         GREY WOLF INTERNATIONAL, INC.,

                           GREY WOLF HOLDINGS COMPANY,

                                 GREY WOLF LLC,

                       GREY WOLF MEXICO HOLDINGS LLC, and

                           MURCO DRILLING CORPORATION,

                               as the Guarantors,


                                       and


                        DEUTSCHE BANK SECURITIES INC. and

                         CREDIT SUISSE FIRST BOSTON LLC

                            as the Initial Purchasers
           Floating Rate Contingent Convertible Senior Notes Due 2024





<PAGE>
                                TABLE OF CONTENTS

<TABLE>
<C>                                                                                       <C>
1.       Definitions.......................................................................1

2.       Shelf Registration................................................................4

3.       Liquidated Damages................................................................6

4.       Registration Procedures...........................................................7

5.       Registration Expenses............................................................14

6.       Indemnification..................................................................14

7.       Rules 144 and 144A...............................................................18

8.       Underwritten Registrations.......................................................18

9.       Miscellaneous....................................................................19
</TABLE>



                                       ii

<PAGE>
                          REGISTRATION RIGHTS AGREEMENT

         This Registration Rights Agreement (this "AGREEMENT") is dated as of
March 31, 2004, by and between GREY WOLF, INC., a Texas corporation (the
"COMPANY"), each of the subsidiaries listed on Schedule A attached hereto (each
a "GUARANTOR" and, collectively, the "GUARANTORS"), and DEUTSCHE BANK SECURITIES
INC. and CREDIT SUISSE FIRST BOSTON LLC (together, the "INITIAL PURCHASERS").

         This Agreement is entered into in connection with that certain Purchase
Agreement, dated March 25, 2004 (the "PURCHASE AGREEMENT"), by and between the
Company, the Guarantors and the Initial Purchasers, which provides for the sale
by the Company to the Initial Purchasers of $100,000,000 aggregate principal
amount of the Company's Floating Rate Contingent Convertible Senior Notes Due
2024 (the "FIRM SECURITIES"), which are convertible into common stock of the
Company, par value $0.10 per share (together with the Rights (as defined in the
Purchase Agreement), the "UNDERLYING SHARES"), plus up to an additional
$25,000,000 aggregate principal amount of the same which the Initial Purchasers
may subsequently elect to purchase pursuant to the terms of the Purchase
Agreement (the "OPTION SECURITIES" and together with the Firm Securities, the
"SECURITIES"). The Securities are being issued pursuant to an Indenture dated as
of the date hereof (the "INDENTURE"), by and between the Company and JPMorgan
Chase Bank, as trustee.

         In order to induce the Initial Purchasers to enter into the Purchase
Agreement, the Company and Guarantors have agreed to provide the registration
rights set forth in this Agreement for the benefit of the Initial Purchasers and
certain subsequent holder or holders of the Securities or Underlying Shares as
provided herein. The execution and delivery of this Agreement is a condition to
the Initial Purchasers' obligation to purchase the Firm Securities under the
Purchase Agreement.

         The parties hereby agree as follows:

1.       Definitions. As used in this Agreement, the following terms shall have
         the following meanings:

         AGREEMENT: See the first introductory paragraph hereto.

         AMOUNT OF REGISTRABLE SECURITIES: (a) With respect to Securities
constituting Registrable Securities, the aggregate principal amount of all such
Securities outstanding, (b) with respect to Underlying Shares constituting
Registrable Securities, the aggregate number of such Underlying Shares
outstanding multiplied by the Conversion Price (as defined in the Indenture
relating to the Securities upon the conversion of which such Underlying Shares
were issued) in effect at the time of computing the Amount of Registrable
Securities or, if no such Securities are then outstanding, the last Conversion
Price that was in effect under such Indenture when any such Securities were last
outstanding, and (c) with respect to combinations thereof, the sum of (a) and
(b) for the relevant Registrable Securities.

         BUSINESS DAY: Any day that is not a Saturday, Sunday or a day on which
banking institutions in New York or Houston, Texas are authorized or required by
law to be closed.

<PAGE>
         CLOSING DATE: March 31, 2004.

         COMPANY: See the first introductory paragraph hereto.

         DAMAGES PAYMENT DATE: See Section 3(c) hereof.

         DEPOSITARY: The Depository Trust Company until a successor is appointed
by the Company.

         EFFECTIVENESS DATE: The 180th day after the Closing Date.

         EFFECTIVENESS PERIOD: See Section 2(a) hereof.

         EXCHANGE ACT: The Securities Exchange Act of 1934, as amended, and the
rules and regulations of the SEC promulgated thereunder.

         FILING DATE: The 90th day after the Closing Date.

         GUARANTORS: See the first introductory paragraph hereto.

         HOLDER: Any holder of Registrable Securities.

         INDEMNIFIED HOLDER: See Section 6 hereof.

         INDEMNIFIED PERSON: See Section 6 hereof.

         INDEMNIFYING PERSON: See Section 6 hereof.

         INDENTURE: See the second introductory paragraph hereto.

         INITIAL PURCHASERS: See the first introductory paragraph hereto.

         INITIAL SHELF REGISTRATION: See Section 2(a) hereof.

         INSPECTORS: See Section 4(n) hereof.

         LIQUIDATED DAMAGES: See Section 3(a) hereof.

         NASD: See Section 4(q) hereof.

         NOTICE AND QUESTIONNAIRE: means a written notice delivered to the
Company containing substantially the information called for by the Form of
Selling Securityholder Notice and Questionnaire attached as Appendix A to the
Offering Memorandum of the Company dated March 25, 2004 relating to the
Securities.

         PERSON: An individual, partnership, corporation, limited liability
company, unincorporated association, trust or joint venture, or a governmental
agency or political subdivision thereof.

                                       2
<PAGE>
         PROSPECTUS: The prospectus included in any Registration Statement
(including, without limitation, any prospectus subject to completion and a
prospectus that includes any information previously omitted from a prospectus
filed as part of an effective registration statement in reliance upon Rule 430A
promulgated under the Securities Act), as amended or supplemented by any
prospectus supplement, and all other amendments and supplements to the
Prospectus, including post-effective amendments, and all material incorporated
by reference or deemed to be incorporated by reference in such Prospectus.

         PURCHASE AGREEMENT: See the second introductory paragraph hereto.

         QIU: See Section 4(q) hereof.

         RECORDS: See Section 4(n) hereof.

         REGISTRABLE SECURITIES: All Securities and all Underlying Shares upon
original issuance thereof and at all times subsequent thereto until the earliest
to occur of (i) a Registration Statement covering such Securities and Underlying
Shares having been declared effective by the SEC and such Securities and
Underlying Shares having been disposed of in accordance with such effective
Registration Statement, (ii) such Securities and Underlying Shares having been
sold in compliance with Rule 144 or could (except with respect to affiliates of
the Company within the meaning of the Securities Act) be sold in compliance with
Rule 144(k), or (iii) such Securities and any Underlying Shares ceasing to be
outstanding.

         REGISTRATION DEFAULT: See Section 3(a) hereof.

         REGISTRATION STATEMENT: Any registration statement of the Company and
the Guarantors filed with the SEC pursuant to the provisions of this Agreement,
including the Prospectus, amendments and supplements to such registration
statement, including post-effective amendments, all exhibits and all material
incorporated by reference or deemed to be incorporated by reference in such
registration statement.

         RULE 144: Rule 144 promulgated under the Securities Act, as such Rule
may be amended from time to time, or any similar rule (other than Rule 144A) or
regulation hereafter adopted by the SEC providing for offers and sales of
securities made in compliance therewith resulting in offers and sales by
subsequent holders that are not affiliates of an issuer of such securities being
free of the registration and prospectus delivery requirements of the Securities
Act.

         RULE 144A: Rule 144A promulgated under the Securities Act, as such Rule
may be amended from time to time, or any similar rule (other than Rule 144) or
regulation hereafter adopted by the SEC.

         RULE 415: Rule 415 promulgated under the Securities Act, as such Rule
may be amended from time to time, or any similar rule or regulation hereafter
adopted by the SEC.

         SEC: The Securities and Exchange Commission.

         SECURITIES: See the second introductory paragraph hereto.

                                       3
<PAGE>

         SECURITIES ACT: The Securities Act of 1933, as amended, and the rules
and regulations of the SEC promulgated thereunder.

         SELLING HOLDER: On any date, any Holder that has delivered a Notice and
Questionnaire to the Company on or prior to such date.

         SHELF REGISTRATION: See Section 2(b) hereof.

         SHELF REGISTRATION STATEMENT: See Section 2(b) hereof.

         SUBSEQUENT SHELF REGISTRATION: See Section 2(b) hereof.

         TIA: The Trust Indenture Act of 1939, as amended, and the rules and
regulations of the SEC promulgated thereunder.

         TRUSTEE: The Trustee under the Indenture.

         UNDERLYING SHARES: See the second introductory paragraph hereto.

         UNDERWRITTEN REGISTRATION OR UNDERWRITTEN OFFERING: A registration in
which securities of the Company are sold to an underwriter for reoffering to the
public.

2.       Shelf Registration.

         (a) Shelf Registration. The Company and the Guarantors shall file with
the SEC a Registration Statement for an offering to be made on a continuous
basis pursuant to Rule 415 covering all of the Registrable Securities (the
"INITIAL SHELF REGISTRATION") on or prior to the Filing Date.

         The Initial Shelf Registration shall be on Form S-3 or another
appropriate form permitting registration of such Registrable Securities for
resale by Holders in the manner or manners designated by them (including,
without limitation, one or more underwritten offerings). The Company and the
Guarantors shall not permit any securities other than the Registrable Securities
to be included in the Initial Shelf Registration or any Subsequent Shelf
Registration (as defined below).

         The Company and the Guarantors shall use all reasonable efforts to
cause the Initial Shelf Registration to be declared effective under the
Securities Act on or prior to the Effectiveness Date and to keep such Initial
Shelf Registration continuously effective under the Securities Act until the
date that is two years from the Closing Date (as it may be shortened pursuant to
clause (i) or clause (ii) immediately following, the "EFFECTIVENESS PERIOD"), or
such shorter period ending when (i) all of the Registrable Securities covered by
the Initial Shelf Registration have been sold in the manner set forth and as
contemplated in the Initial Shelf Registration, (ii) the date on which all the
Registrable Securities (x) held by Persons who are not affiliates of the Company
may be resold pursuant to Rule 144(k) under the Securities Act, or any successor
provision, or (y) cease to be outstanding, or (iii) a Subsequent Shelf
Registration covering all of the Registrable Securities has been declared
effective under the Securities Act.

                                       4
<PAGE>
         (b) Subsequent Shelf Registrations. If the Initial Shelf Registration
or any Subsequent Shelf Registration (as defined below) ceases to be effective
for any reason at any time during the Effectiveness Period (other than because
of the sale of all of the securities registered thereunder), the Company and the
Guarantors shall use all reasonable efforts to obtain the prompt withdrawal of
any order suspending the effectiveness thereof, and in any event shall within 45
days of such cessation of effectiveness amend the Initial Shelf Registration in
a manner to obtain the withdrawal of the order suspending the effectiveness
thereof, or file an additional "shelf" Registration Statement pursuant to Rule
415 covering all of the Registrable Securities (a "SUBSEQUENT SHELF
REGISTRATION"). If a Subsequent Shelf Registration is filed, the Company and the
Guarantors shall use all reasonable efforts to cause the Subsequent Shelf
Registration to be declared effective under the Securities Act as soon as
practicable after such filing and to keep such Registration Statement
continuously effective for a period equal to the number of days in the
Effectiveness Period less the aggregate number of days during which the Initial
Shelf Registration or any Subsequent Shelf Registration was previously
continuously effective. As used herein, the term "SHELF REGISTRATION" means the
Initial Shelf Registration and any Subsequent Shelf Registration and the term
"SHELF REGISTRATION STATEMENT" means any Registration Statement filed in
connection with a Shelf Registration.

         (c) Supplements and Amendments. The Company and the Guarantors shall
promptly supplement and amend the Shelf Registration if required by the rules,
regulations or instructions applicable to the registration form used for such
Shelf Registration, if required by the Securities Act, or if reasonably
requested by the Holders of the majority in Amount of Registrable Securities
covered by such Registration Statement or by any underwriter of such Registrable
Securities.

         (d) Notice and Questionnaire. Each Holder agrees that if such Holder
wishes to sell Registrable Securities pursuant to a Shelf Registration Statement
and related Prospectus, it will do so only in accordance with this Section 2(d)
and Section 4 hereof. Each Holder wishing to sell Registrable Securities
pursuant to a Shelf Registration Statement and related Prospectus agrees to
deliver a Notice and Questionnaire to the Company at least three (3) Business
Days prior to any intended distribution of Registrable Securities under the
Shelf Registration Statement. From and after the date the Initial Shelf
Registration Statement is declared effective, the Company and the Guarantors
shall, as promptly as practicable after the date a Notice and Questionnaire is
delivered, and in any event upon the later of (x) five (5) Business Days after
such date or (y) five (5) Business Days after the expiration of any Deferral
Period in effect when the Notice and Questionnaire is delivered or put into
effect within five (5) Business Days of such delivery date:

                  (i) if required by applicable law, file with the SEC a
         post-effective amendment to the Shelf Registration Statement or prepare
         and, if required by applicable law, file a supplement to the related
         Prospectus or a supplement or amendment to any document incorporated
         therein by reference or file any other required document so that the
         Holder delivering such Notice and Questionnaire is named as a selling
         securityholder in the Shelf Registration Statement and the related
         Prospectus in such a manner as to permit such Holder to deliver such
         Prospectus to purchasers of the Registrable Securities in accordance
         with applicable law and, if the Company and the Guarantors shall file a
         post-effective amendment to the Shelf Registration Statement, use all
         reasonable efforts

                                       5
<PAGE>
         to cause such post-effective amendment to be declared effective under
         the Securities Act as promptly as is practicable, but in any event by
         the date (the "AMENDMENT EFFECTIVENESS DEADLINE DATE") that is
         forty-five (45) days after the date such post-effective amendment is
         required by this clause to be filed;

                  (ii) provide such Holder copies of any documents filed
         pursuant to Section 2(d)(i); and

                  (iii) notify such Holder as promptly as practicable after the
         effectiveness under the Securities Act of any post-effective amendment
         filed pursuant to Section 2(d)(i);

provided that if such Notice and Questionnaire is delivered during a Deferral
Period (as defined in Section 3(b)), the Company shall so inform the Holder
delivering such Notice and Questionnaire and shall take the actions set forth in
clauses (i), (ii) and (iii) above upon expiration of the Deferral Period.
Notwithstanding anything contained herein to the contrary, (i) the Company shall
be under no obligation to name any Holder as a selling security holder in a
Shelf Registration Statement that has not delivered a Notice and Questionnaire
to the Company in accordance with this Section 2(d) and (ii) the Amendment
Effectiveness Deadline Date shall be extended by up to ten (10) Business Days
from the expiration of a Deferral Period (and the Company shall incur no
obligation to pay Liquidated Damages during such extension) if such Deferral
Period shall be in effect on the Amendment Effectiveness Deadline Date.

3.       Liquidated Damages.

         (a) The Company and the Initial Purchasers agree that the Holders of
Registrable Securities will suffer damages if the Company and the Guarantors
fail to fulfill certain of their obligations under Section 2 hereof and that it
would not be feasible to ascertain the extent of such damages with precision.
Accordingly, the Company agrees to pay liquidated damages on the Registrable
Securities ("LIQUIDATED DAMAGES") under the circumstances and to the extent set
forth below (each of which shall be given independent effect; each a
"REGISTRATION DEFAULT"):

                  (i) if the Initial Shelf Registration is not filed on or prior
         to the Filing Date, then commencing on the day after the Filing Date,
         Liquidated Damages shall accrue on the Registrable Securities at a rate
         of 0.50% per annum on the Amount of Registrable Securities;

                  (ii) if the Initial Shelf Registration is not declared
         effective by the SEC on or prior to the Effectiveness Date, then
         commencing on the day after the Effectiveness Date, Liquidated Damages
         shall accrue on the Registrable Securities at a rate of 0.50% per annum
         on the Amount of Registrable Securities; and

                  (iii) if a Shelf Registration has been declared effective and
         such Shelf Registration ceases to be effective at any time during the
         Effectiveness Period (other than as permitted under Section 3(b)), then
         Liquidated Damages shall accrue on the Registrable Securities at a rate
         of 0.50% per annum on the Amount of Registrable Securities;

                                       6
<PAGE>
provided, however, that Liquidated Damages on the Registrable Securities may not
accrue under more than one of the foregoing clauses (i), (ii) or (iii) at any
one time; and provided further, however, that (1) upon the filing of the Initial
Shelf Registration as required hereunder (in the case of clause (a)(i) of this
Section 3), (2) upon the effectiveness of the Initial Shelf Registration as
required hereunder (in the case of clause (a)(ii) of this Section 3), or (3)
upon the effectiveness of a Shelf Registration which had ceased to remain
effective (in the case of (a)(iii) of this Section 3), Liquidated Damages on the
Registrable Securities as a result of such clause (or the relevant subclause
thereof), as the case may be, shall cease to accrue. It is understood and agreed
that, notwithstanding any provision to the contrary, no Liquidated Damages shall
accrue on any Registrable Securities that are then covered by an effective Shelf
Registration Statement.

         (b) Notwithstanding paragraph (a) of this Section 3, the Company shall
be permitted to suspend the effectiveness of a Registration Statement covering
the Registrable Securities for any reason whatsoever for up to 30 consecutive
days (the "DEFERRAL PERIOD") in any 90 day period, for a total of not more than
90 days in any twelve-month period, without paying Liquidated Damages.

         (c) So long as Securities remain outstanding, the Company shall notify
the Trustee within two Business Days after each and every date on which an event
occurs in respect of which Liquidated Damages is required to be paid. Any
amounts of Liquidated Damages due pursuant to clause (a)(i), (a)(ii) or (a)(iii)
of this Section 3 will be payable in cash quarterly on each January 1, April 1,
July 1 and October 1 (each, a "DAMAGES PAYMENT DATE"), commencing with the first
such date occurring after any such Liquidated Damages commences to accrue, to
Holders to whom regular interest is payable on such Damages Payment Date, with
respect to Securities that are Registrable Securities, and to Persons that are
registered Holders on the March 15, June 15, September 15 or December 15
immediately prior to a Damages Payment Date with respect to Underlying Shares
that are Registrable Securities. The amount of Liquidated Damages for
Registrable Securities will be determined by multiplying the applicable rate of
Liquidated Damages by the Amount of Registrable Securities outstanding on the
Damages Payment Date following such Registration Default in the case of the
first such payment of Liquidated Damages with respect to a Registration Default
(and thereafter at the next succeeding Damages Payment Date until the cure of
such Registration Default), multiplied by a fraction, the numerator of which is
the number of days such Liquidated Damages rate was applicable during such
period (determined on the basis of a 360-day year comprised of twelve 30-day
months and, in the case of a partial month, the actual number of days elapsed),
and the denominator of which is 360.

4.       Registration Procedures.

         In connection with the filing of any Registration Statement pursuant to
Section 2 hereof, the Company and the Guarantors shall effect such registrations
to permit the sale of the securities covered thereby in accordance with the
intended method or methods of disposition thereof, and pursuant thereto and in
connection with any Registration Statement filed by the Company and the
Guarantors hereunder the Company and the Guarantors, as applicable, shall:

         (a) Prepare and file with the SEC, on or prior to the Filing Date, a
Registration Statement or Registration Statements as prescribed by Section 2
hereof, and use all reasonable efforts to cause each such Registration Statement
to become effective and remain effective as

                                       7
<PAGE>
provided herein; provided, however, that before filing any Registration
Statement or Prospectus or any amendments or supplements thereto (excluding
materials filed pursuant to the Exchange Act and incorporated by reference
therein), the Company shall furnish to and afford the Holders of the Registrable
Securities covered by such Registration Statement and the managing underwriter
or underwriters, if any, a reasonable opportunity to review copies of all such
documents proposed to be filed (in each case, where possible, at least five
Business Days prior to such filing, or such later date as is reasonable under
the circumstances) and if such proposed filings contain material non-public
information, such persons must enter into a confidentiality agreement with
respect to such information if reasonably requested by the Company. The Company
and the Guarantors shall not file any Registration Statement or Prospectus or
any amendments or supplements thereto if the Holders of a majority in Amount of
Registrable Securities covered by such Registration Statement or the managing
underwriter or underwriters, if any, shall reasonably object.

         (b) Prepare and file with the SEC such amendments and post-effective
amendments to each Shelf Registration, as may be necessary to keep such
Registration Statement continuously effective for the Effectiveness Period;
cause the related Prospectus to be supplemented by any Prospectus supplement
required by applicable law, and as so supplemented to be filed pursuant to Rule
424 (or any similar provisions then in force) promulgated under the Securities
Act; and comply with the provisions of the Securities Act and the Exchange Act
applicable to it with respect to the disposition of all Registrable Securities
covered by such Registration Statement as so amended or in such Prospectus as so
supplemented. The Company and the Guarantors shall be deemed not to have used
all reasonable efforts to keep a Registration Statement effective during the
Effectiveness Period if any of them voluntarily takes any action that would
result in Selling Holders of the Registrable Securities covered thereby not
being able to sell such Registrable Securities during that period unless such
action is required by applicable law or unless the Company and the Guarantors
comply with this Agreement, including without limitation the provisions of
Section 4(k) hereof.

         (c) Notify the Selling Holders, a single counsel to such Holders
(chosen in accordance with Section 5(b)) and the managing underwriter or
underwriters, if any, promptly (but in any event within two Business Days), (i)
when a Prospectus or any prospectus supplement or post-effective amendment has
been filed, and, with respect to a Registration Statement or any post-effective
amendment, when the same has become effective under the Securities Act
(including in such notice a written statement that any Holder may, upon request,
obtain, at the sole expense of the Company, one conformed copy of such
Registration Statement or post-effective amendment including financial
statements and schedules, documents incorporated or deemed to be incorporated by
reference and exhibits), (ii) of the issuance by the SEC of any stop order
suspending the effectiveness of a Registration Statement or of any order
preventing or suspending the use of any preliminary prospectus or the initiation
of any proceedings for that purpose, (iii) of the happening of any event, the
existence of any condition or any information becoming known that makes any
statement made in such Registration Statement or related Prospectus or any
document incorporated or deemed to be incorporated therein by reference untrue
in any material respect or that requires the making of any changes in or
amendments or supplements to such Registration Statement, Prospectus or
documents so that, in the case of the Registration Statement, it will not
contain any untrue statement of a material fact or omit to state any material
fact required to be stated therein or necessary to make the

                                       8
<PAGE>
statements therein not misleading, and that in the case of the Prospectus, it
will not contain any 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 the light of the circumstances under which they were made, not
misleading and (iv) of the Company's or any Guarantor's determination that a
post-effective amendment to a Registration Statement would be appropriate.

         (d) Use all reasonable efforts to prevent the issuance of any order
suspending the effectiveness of a Registration Statement or of any order
preventing or suspending the use of a Prospectus and, if any such order is
issued, to use all reasonable efforts to obtain the withdrawal of any such order
at the earliest possible moment, and provide immediate notice to the Selling
Holders and the managing underwriter or underwriters, if any, of the withdrawal
of any such order.

         (e) If requested by the managing underwriter or underwriters, if any,
or the Holders of the majority in Amount of Registrable Securities being sold in
connection with an underwritten offering (i) promptly incorporate in a
prospectus supplement or post-effective amendment such information as the
managing underwriter or underwriters (if any), or such Holders reasonably
determine is necessary to be included therein, (ii) make all required filings of
such prospectus supplement or such post-effective amendment as soon as
reasonably practicable after the Company has received notification of the
matters to be incorporated in such prospectus supplement or post-effective
amendment and (iii) supplement or make amendments to such Registration
Statement.

         (f) Furnish to each Selling Holder, a single counsel to such Holders
(chosen in accordance with Section 5(b)) and the managing underwriter or
underwriters, if any, at the sole expense of the Company, one conformed copy of
the Registration Statement or Registration Statements and each post-effective
amendment thereto, including financial statements and schedules, and, if
requested, all documents incorporated or deemed to be incorporated therein by
reference and all exhibits.

         (g) Deliver to each Selling Holder, a single counsel to such Holders
(chosen in accordance with Section 5(b)) and the managing underwriter or
underwriters, if any, at the sole expense of the Company, as many copies of the
Prospectus (including each form of preliminary prospectus) and each amendment or
supplement thereto and any documents incorporated by reference therein as such
Persons may reasonably request; and, subject to the second paragraph of Section
4(s) hereof, the Company and the Guarantors hereby consent to the use of such
Prospectus and each amendment or supplement thereto by each of the Selling
Holders of Registrable Securities and the managing underwriter or underwriters
or agents, if any, and dealers (if any), in connection with the offering and
sale of the Registrable Securities covered by such Prospectus and any amendment
or supplement thereto.

         (h) Prior to any public offering of Registrable Securities, to use all
reasonable efforts to register or qualify, to the extent required by applicable
law, and to cooperate with the Selling Holders and the managing underwriter or
underwriters, if any, and their respective counsel in connection with the
registration or qualification (or exemption from such registration or
qualification) of such Registrable Securities or offer and sale under the
securities or Blue Sky laws of such jurisdictions within the United States as
any selling Holder, or the managing

                                       9
<PAGE>

underwriter or underwriters, if any, reasonably request; provided, however, that
where Registrable Securities are offered other than through an underwritten
offering, the Company and the Guarantors agree to cause the Company's counsel to
perform Blue Sky investigations and file registrations and qualifications
required to be filed pursuant to this Section 4(h); keep each such registration
or qualification (or exemption therefrom) effective during the period such
Registration Statement is required to be kept effective and do any and all other
acts or things reasonably necessary or advisable to enable the disposition in
such jurisdictions of the Registrable Securities covered by the applicable
Registration Statement; provided, however, that the Company and the Guarantors
shall not be required to (A) qualify generally to do business in any
jurisdiction where it is not then so qualified, (B) take any action that would
subject it to general service of process in any such jurisdiction where it is
not then so subject or (C) subject itself to taxation in excess of a nominal
dollar amount in any such jurisdiction where it is not then so subject.

         (i) Cooperate with the Selling Holders and the managing underwriter or
underwriters, if any, and their respective counsel to facilitate the timely
preparation and delivery of certificates representing shares of Registrable
Securities to be sold, which certificates shall not bear any restrictive legends
and shall be in a form eligible for deposit with The Depository Trust Company;
and enable such shares of Registrable Securities to be in such denominations and
registered in such names as the managing underwriter or underwriters, if any, or
Holders may reasonably request.

         (j) Use all reasonable efforts to cause the Registrable Securities
covered by any Shelf Registration Statement to be registered with or approved by
such other governmental agencies or authorities as may be reasonably necessary
to enable the Selling Holder or Holders thereof or the managing underwriter or
underwriters, if any, to consummate the disposition of such Registrable
Securities, except as may be required solely as a consequence of the nature of
such selling Holder's business, in which case the Company and the Guarantors
will cooperate in all reasonable respects with the filing of such Registration
Statement and the granting of such approvals.

         (k) Upon the occurrence of any event contemplated by paragraph
4(c)(ii), 4(c)(iii) or 4(c)(iv) hereof, as promptly as practicable prepare and
(subject to Section 4(a) hereof) file with the SEC, at the sole expense of the
Company, a supplement or post-effective amendment to the Registration Statement
or a supplement to the related Prospectus or any document incorporated or deemed
to be incorporated therein by reference, or file any other required document so
that, as thereafter delivered to the purchasers of the Registrable Securities
being sold thereunder, any such Prospectus will not 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, in the light of the
circumstances under which they were made, not misleading.

         (l) Prior to the effective date of the first Registration Statement
relating to the Registrable Securities, (i) provide the Trustee with
certificates for the Registrable Securities in a form eligible for deposit with
The Depository Trust Company and (ii) provide a CUSIP number for the Registrable
Securities.

                                       10
<PAGE>
         (m) In connection with any underwritten offering of Registrable
Securities pursuant to a Shelf Registration, enter into an underwriting
agreement as is customary in underwritten offerings of securities similar to the
Registrable Securities and take all such other actions as are reasonably
requested by the managing underwriter or underwriters in order to expedite or
facilitate the registration or the disposition of such Registrable Securities
and, in such connection, (i) make such representations and warranties to, and
covenants with, the managing underwriter or underwriters with respect to the
business of the Company and its subsidiaries (including any acquired business,
properties or entity, if applicable) and the Registration Statement, Prospectus
and documents, if any, incorporated or deemed to be incorporated by reference
therein, in each case, as are customarily made by issuers to underwriters in
underwritten offerings of securities similar to the Registrable Securities and
confirm the same in writing if and when requested; (ii) obtain the written
opinion of counsel to the Company and the Guarantors and written updates thereof
in form, scope and substance reasonably satisfactory to the managing underwriter
or underwriters, addressed to the managing underwriter or underwriters covering
the matters customarily covered in opinions requested in underwritten offerings
of securities similar to the Registrable Securities and such other matters as
may be reasonably requested by the managing underwriter or underwriters; and
(iii) obtain "cold comfort" letters and updates thereof in form, scope and
substance reasonably satisfactory to the managing underwriter or underwriters
from the independent certified public accountants of the Company (and, if
necessary, any other independent certified public accountants of any subsidiary
of the Company or of any business acquired by the Company for which financial
statements and financial data are, or are required to be, included or
incorporated by reference in the Registration Statement), addressed to each of
the underwriters, such letters to be in customary form and covering matters of
the type customarily covered in "cold comfort" letters in connection with
underwritten offerings of securities similar to the Registrable Securities and
such other matters as reasonably requested by the managing underwriter or
underwriters as permitted by the Statement on Auditing Standards No. 72. The
above shall be done as and to the extent required by such underwriting
agreement.

         (n) Make available for inspection by any Selling Holder of such
Registrable Securities being sold, any managing underwriter or underwriters
participating in any such disposition of Registrable Securities, if any, and any
attorney, accountant or other agent retained by any such Selling Holder or
underwriter (collectively, the "INSPECTORS"), at the offices where normally
kept, during reasonable business hours at such time or times as shall be
mutually convenient for the Company and the Inspectors as a group, all financial
and other records, pertinent corporate documents and instruments of the Company
and its subsidiaries (collectively, the "RECORDS") as shall be reasonably
necessary to enable them to exercise any applicable due diligence
responsibilities, and cause the officers, directors and employees of the Company
and its subsidiaries to supply all information reasonably requested by any such
Inspector in connection with such Registration Statement. Records that the
Company determines, in good faith, to be confidential and any Records that it
notifies the Inspectors are confidential shall not be disclosed by any Inspector
unless (i) the disclosure of such Records is necessary to avoid or correct a
material misstatement or material omission in such Registration Statement, (ii)
the release of such Records is ordered pursuant to a subpoena or other order
from a court of competent jurisdiction, (iii) disclosure of such information is,
in the opinion of counsel for any Inspector, necessary or advisable in
connection with any action, claim, suit or proceeding, directly involving or
potentially involving such Inspector and arising out of, based upon, relating
to, or

                                       11
<PAGE>
involving this Agreement or any transactions contemplated hereby or arising
hereunder or (iv) the information in such Records has been made generally
available to the public other than through the acts of such Inspector; provided,
however, that prior notice shall be provided as soon as practicable to the
Company of the potential disclosure of any information by such Inspector
pursuant to clauses (ii) or (iii) of this sentence to permit the Company to
obtain a protective order (or waive the provisions of this paragraph (n)). Each
Inspector shall take such actions as are reasonably necessary to protect the
confidentiality of such information (if practicable) to the extent such actions
are otherwise not inconsistent with, an impairment of or in derogation of the
rights and interests of the Holder or any Inspector, unless and until such
information in such Records has been made generally available to the public
other than as a result of a breach of this Agreement.

         (o) Provide (i) the Holders of the Registrable Securities to be
included in such Registration Statement and not more than one counsel for all
the Holders of such Registrable Securities chosen in accordance with Section
5(b), (ii) the managing underwriter or underwriters (which term, for purposes of
this Registration Rights Agreement, shall include a Person deemed to be an
underwriter within the meaning of Section 2(11) of the Securities Act), if any,
thereof, (iii) the sales or placement agent, if any, thereof, and (iv) one
counsel for such underwriters or agents, reasonable opportunity to participate
in the preparation of such Registration Statement, each prospectus included
therein or filed with the SEC, and each amendment or supplement thereto.

         (p) Comply with all applicable rules and regulations of the SEC and
make generally available to its security holders earning statements satisfying
the provisions of Section 11(a) of the Securities Act and Rule 158 thereunder
(or any similar rule promulgated under the Securities Act) no later than 45 days
after the end of any 12-month period (or 90 days after the end of any 12-month
period if such period is a fiscal year) (i) commencing at the end of any fiscal
quarter in which Registrable Securities are sold to underwriters in a firm
commitment or best efforts underwritten offering and (ii) if not sold to
underwriters in such an offering, commencing on the first day of the first
fiscal quarter of the Company after the effective date of a Registration
Statement, which statements shall cover said 12-month periods.

         (q) Cooperate with each Selling Holder of Registrable Securities
covered by any Registration Statement and the managing underwriter or
underwriters, if any, participating in the disposition of such Registrable
Securities and their respective counsel in connection with any filings required
to be made with the National Association of Securities Dealers, Inc. (the
"NASD"), including, if the Conduct Rules of the NASD or any successor thereto as
amended from time to time so require, engaging a "qualified independent
underwriter" ("QIU") as contemplated therein and making Records available to
such QIU as though it were a participating underwriter for the purposes of
Section 4(n) and otherwise applying the provisions of this Agreement to such QIU
(including indemnification) as though it were a participating underwriter.

         (r) Cause the Indenture to be qualified under the TIA not later than
the effective date of the first Registration Statement relating to the
Registrable Securities; and in connection therewith, cooperate with the Trustee
and the Holders of the Registrable Securities and their respective counsel to
effect such changes to the Indenture as may be required for the Indenture to

                                       12
<PAGE>
be so qualified in accordance with the terms of the TIA; and execute, and use
all reasonable efforts to cause the Trustee to execute, all documents as may be
required to effect such changes and all other forms and documents required to be
filed with the SEC to enable the Indenture to be so qualified in a timely
manner.

         (s) Use all reasonable efforts to take all other steps necessary or
advisable to effect the registration of the Registrable Securities covered by a
Registration Statement contemplated hereby.

         Each Holder agrees, by acquisition of the Registrable Securities, that
no Holder shall be entitled to sell any of such Registrable Securities pursuant
to a Registration Statement or to receive a Prospectus relating thereto, unless
such Holder has furnished the Company with a Notice and Questionnaire as
required pursuant to Section 2(d) hereof (including the information required to
be included in such Notice and Questionnaire) and the information set forth in
the next sentence. Each Selling Holder agrees promptly to furnish to the Company
all information required to be disclosed in order to make the information
previously furnished to the Company by such Selling Holder not misleading and
any other information regarding such Selling Holder and the distribution of such
Registrable Securities as the Company may from time to time reasonably request.
Any sale of any Registrable Securities by any Holder shall constitute a
representation and warranty by such Holder that the information relating to such
Holder and its plan of distribution is as set forth in the Prospectus delivered
by such Holder in connection with such disposition, that such Prospectus does
not as of the time of such sale contain any untrue statement of a material fact
relating to or provided by such Holder or its plan of distribution and that such
Prospectus does not as of the time of such sale omit to state any material fact
relating to or provided by such Holder or its plan of distribution necessary to
make the statements in such Prospectus, in the light of the circumstances under
which they were made, not misleading.

         The Company may require each Selling Holder of Registrable Securities
as to which any registration is being effected to furnish to the Company such
additional information regarding such Holder and the distribution of such
Registrable Securities as the Company may, from time to time, reasonably request
to the extent necessary or advisable to comply with the Securities Act. The
Company may exclude from such registration the Registrable Securities of any
Selling Holder if such Holder fails to furnish such additional information
within 20 Business Days after receiving such request. Each Selling Holder as to
which any Shelf Registration is being effected agrees to furnish promptly to the
Company all information required to be disclosed so that the information
previously furnished to the Company by such Holder is not materially misleading
and does not 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.

         Each Holder of Registrable Securities agrees by acquisition of such
Registrable Securities that, upon actual receipt of any notice from the Company
of the Company suspending the effectiveness of the Registration Statement
pursuant to Section 3(b) hereof, or upon the happening of any event of the kind
described in Section 4(c)(ii), 4(c)(iii) or 4(c)(iv) hereof, such Holder will
forthwith discontinue disposition of such Registrable Securities covered by such
Registration Statement or Prospectus until such Holder's receipt of the copies
of the supplemented or amended Prospectus contemplated by Section 4(k) hereof,
or until it is advised

                                       13
<PAGE>
in writing by the Company that the use of the applicable Prospectus may be
resumed, and has received copies of any amendments or supplements thereto.

5.       Registration Expenses.

         (a) All fees and expenses incident to the performance of or compliance
with this Agreement by the Company and the Guarantors shall be borne by the
Company and the Guarantors, as the case may be, including, without limitation,
(i) all registration and filing fees (including, without limitation, (A) fees
with respect to filings required to be made with the NASD in connection with an
underwritten offering and (B) fees and expenses of compliance with state
securities or Blue Sky laws (including, without limitation, reasonable fees and
disbursements of counsel in connection with Blue Sky qualifications of the
Registrable Securities and determination of the eligibility of the Registrable
Securities for investment under the laws of such jurisdictions as provided in
Section 4(h) hereof), (ii) printing expenses, including, without limitation,
expenses of printing certificates for Registrable Securities in a form eligible
for deposit with The Depository Trust Company and of printing prospectuses if
the printing of prospectuses is requested by the managing underwriter or
underwriters, if any, or by the Holders of the majority in Amount of Registrable
securities included in any Registration Statement, (iii) messenger, telephone
and delivery expenses, (iv) fees and disbursements of counsel for the Company,
(v) fees and disbursements of all independent certified public accountants
referred to in Section 4(m)(iii) hereof (including, without limitation, the
expenses of any special audit and "cold comfort" letters required by or incident
to such performance), (vi) Securities Act liability insurance, if the Company
desires such insurance, (vii) fees and expenses of all other Persons retained by
the Company, (viii) internal expenses of the Company (including, without
limitation, all salaries and expenses of officers and employees of the Company
performing legal or accounting duties), (ix) the expense of any annual audit,
(x) the fees and expenses incurred in connection with the listing of the
securities to be registered on any securities exchange, if applicable, and (xi)
the expenses relating to printing, word processing and distributing all
Registration Statements, underwriting agreements, securities sales agreements
and any other documents necessary in order to comply with this Agreement.
Notwithstanding anything in this Agreement to the contrary, each Holder shall
pay all underwriting discounts and brokerage commissions with respect to any
Registrable Securities sold by it, and the Company shall not be responsible for
the fees and expenses of any counsel for the managing underwriter or
underwriters, if any.

         (b) The Company shall reimburse the Holders of the Registrable
Securities being registered in a Shelf Registration for the reasonable fees and
disbursements of either (i) Akin Gump Strauss Hauer & Feld LLP or (ii) not more
than one counsel chosen by the Holders of a majority in Amount of Registrable
Securities to be included in such Registration Statement.

6.       Indemnification.

         The Company and the Guarantors agree, jointly and severally, to
indemnify and hold harmless (i) each Holder (which, for the absence of doubt,
for purposes of this Section 6 shall include the Initial Purchasers), (ii) each
Person, if any, who controls (within the meaning of either Section 15 of the
Securities Act or Section 20 of the Exchange Act) any Holder (any of the Persons
referred to in this clause (ii) being hereinafter referred to as a "CONTROLLING
PERSON"),

                                       14
<PAGE>
(iii) the respective officers, directors, partners, employees, representatives
and agents of any Holder (including any predecessor holder)or any controlling
person (any person referred to in clause (i), (ii) or (iii) may hereinafter be
referred to as an "INDEMNIFIED HOLDER"), against any losses, claims, damages or
liabilities to which such Indemnified Holder may become subject under the
Securities Act or otherwise, insofar as such losses, claims, damages or
liabilities (or actions or proceedings in respect thereof) arise out of or are
based upon (A) any untrue statement or alleged untrue statement of any material
fact contained in any Registration Statement or Prospectus, or any amendment or
supplement thereto or any related preliminary prospectus or (B) the omission or
alleged omission to state therein a material fact required to be stated therein
or necessary to make the statements therein not misleading, in the light of the
circumstances in which they were made; provided, however, that the Company and
the Guarantors will not be liable under this paragraph, (x) to the extent that
any such loss, claim, damage or liability arises out of or is based upon an
untrue statement or alleged untrue statement, or omission or alleged omission
made in any such Registration Statement or Prospectus, or any amendment or
supplement thereto or any related preliminary prospectus in reliance upon and in
conformity with written information relating to any Holder furnished to the
Company by or on behalf of such Holder specifically for use therein or (y) with
respect to any untrue statement or alleged untrue statement, or omission or
alleged omission made in any preliminary prospectus if the person asserting any
such loss, claim, damage or liability who purchased Registrable Securities which
are the subject thereof did not receive a copy of the Prospectus (or of the
preliminary prospectus as then amended or supplemented if the Company shall have
furnished such Indemnified Holder with such amendment or supplement thereto on a
timely basis) at or prior to the written confirmation of the sale of such
Registrable Securities to such person and, in any case where such delivery is
required by applicable law and the untrue statement or alleged untrue statement
or omission or alleged omission of a material fact made in such preliminary
prospectus was corrected in the Prospectus (or the preliminary prospectus as
then amended or supplemented if the Company shall have furnished such
Indemnified Holder with such amendment or supplement thereto on a timely basis).
The Company shall notify such Indemnified Holder promptly of the institution,
threat or assertion of any claim, proceeding (including any governmental
investigation) or litigation in connection with the matters addressed by this
Agreement which involves the Company or such Indemnified Holder.

         The Company and the Guarantors agree, jointly and severally, to
reimburse each Indemnified Holder upon demand for any legal or other
out-of-pocket expenses reasonably incurred by such Indemnified Holder in
connection with investigating or defending any such loss, claim, damage or
liability, action or proceeding or in responding to a subpoena or governmental
inquiry related to the offering of the Registrable Securities, whether or not
such Indemnified Holder is a party to any action or proceeding. In the event
that it is finally judicially determined that an Indemnified Holder was not
entitled to receive payments for legal and other expenses pursuant to this
paragraph, such Indemnified Holder will promptly return all sums that had been
advanced pursuant hereto.

         Each Holder agrees, severally and not jointly, to indemnify and hold
harmless the Company and the Guarantors, their respective directors and officers
and each Person who controls the Company or the Guarantors (within the meaning
of either Section 15 of the Securities Act or Section 20 of the Exchange Act) to
the same extent as the indemnity provided in the first paragraph of this Section
6 from the Company and the Guarantors to each Holder, but

                                       15
<PAGE>
only with reference to such losses, claims, damages or liabilities which are
caused by any untrue statement or omission or alleged untrue statement or
omission made in reliance upon and in conformity with information relating to a
Holder furnished to the Company in writing by such Holder expressly for use in
any Registration Statement or Prospectus, or any amendment or supplement thereto
or any related preliminary prospectus.

         In case any proceeding (including any governmental investigation) shall
be instituted involving any Person in respect of which indemnity may be sought
pursuant to either of the first and third paragraphs of this Section 6, such
Person (the "INDEMNIFIED PERSON") shall promptly notify the Person or Persons
against whom such indemnity may be sought (each an "INDEMNIFYING PERSON") in
writing. No indemnification provided for in the first or third paragraphs of
this Section 6 shall be available to any Person who shall have failed to give
notice as provided in this paragraph if the party to whom notice was not given
was unaware of the proceeding to which such notice would have related and was
materially prejudiced by the failure to give such notice, but the failure to
give such notice shall not relieve the Indemnifying Person or Persons from any
liability which it or they may have to the Indemnified Person for contribution
or otherwise than on account of the provisions of the first and third paragraphs
of this Section 6. In case any such proceeding shall be brought against any
Indemnified Person and it shall notify the Indemnifying Person of the
commencement thereof, the Indemnifying Person shall be entitled to participate
therein and, to the extent that it shall wish, jointly with any other
Indemnifying Person similarly notified, to assume the defense thereof, with
counsel reasonably satisfactory to such Indemnified Person and shall pay as
incurred (or within 30 days of presentation) the fees and disbursements of such
counsel related to such proceeding. In any such proceeding, any Indemnified
Person shall have the right to retain its own counsel at its own expense.
Notwithstanding the foregoing, the Indemnifying Person shall pay as incurred (or
within 30 days of presentation) the fees and expenses of the counsel retained by
the Indemnified Person in the event (i) the Indemnifying Person and the
Indemnified Person shall have mutually agreed to the retention of such counsel,
(ii) the named parties to any such proceeding (including any impleaded parties)
include both the Indemnifying Person and the Indemnified Person and
representation of both parties by the same counsel would be inappropriate due to
actual or potential differing interests between them or (iii) the Indemnifying
Person shall have failed to assume the defense and employ counsel reasonably
acceptable to the Indemnified Person within a reasonable period of time after
notice of commencement of the action. It is understood that the Indemnifying
Person shall not, in connection with any proceeding or related proceedings in
the same jurisdiction, be liable for the reasonable fees and expenses of more
than one separate firm for all such Indemnified Persons. Such firm shall be
designated in writing by a majority in Amount of Registrable Securities in the
case of parties indemnified pursuant to the first paragraph of this Section 6
and by the Company in the case of parties indemnified pursuant to the third
paragraph of this Section 6. The Indemnifying Person shall not be liable for any
settlement of any proceeding effected without its written consent but if settled
with such consent or if there be a final judgment for the plaintiff, the
Indemnifying Person agrees to indemnify the Indemnified Person from and against
any loss or liability by reason of such settlement or judgment. In addition, the
Indemnifying Person will not, without the prior written consent of the
Indemnified Person, settle or compromise or consent to the entry of any judgment
in any pending or threatened claim, action or proceeding of which
indemnification may be sought hereunder (whether or not any Indemnified Person
is an actual or potential party to such claim, action or

                                       16
<PAGE>
proceeding) unless such settlement, compromise or consent includes an
unconditional release of each Indemnified Person from all liability arising out
of such claim, action or proceeding.

         To the extent the indemnification provided for in this Section 6 is
unavailable to or insufficient to hold harmless an Indemnified Person under the
first or third paragraph of this Section 6 in respect of any losses, claims,
damages or liabilities (or actions or proceedings in respect thereof) referred
to therein, except by reason of the exceptions set forth in the first or third
paragraphs of this Section 6 or the failure of the Indemnified Person to give
notice as required in the fourth paragraph of this Section 6, then each
Indemnifying Person shall contribute to the amount paid or payable by such
Indemnified Person as a result of such losses, claims, damages or liabilities
(or actions or proceedings in respect thereof) in such proportion as is
appropriate to reflect the relative benefits received by the Indemnifying Person
on the one hand and the Indemnified Person on the other hand from the offering
of the Securities pursuant to the Purchase Agreement and the Registrable
Securities pursuant to any Shelf Registration. If, however, the allocation
provided by the immediately preceding sentence is not permitted by applicable
law then each Indemnifying Person shall contribute to such amount paid or
payable by such Indemnified Person in such proportion as is appropriate to
reflect not only such relative benefits but also the relative fault of the
Indemnifying Person on the one hand and the Indemnified Person on the other in
connection with the statements or omissions which resulted in such losses,
claims, damages or liabilities (or actions or proceedings in respect thereof),
as well as any other relevant equitable considerations. The relative benefits
received by the Company and the Guarantors on the one hand and any Indemnified
Holder on the other shall be deemed to be in the same proportion as the total
net proceeds (before deducting expenses) received by the Company and the
Guarantors from the offering and sale of the Securities bear to the total net
proceeds received by such Indemnified Holder from sales of Registrable
Securities giving rise to such obligations. The relative fault 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 and the
Guarantors on the one hand or such Indemnified Holder on the other and the
parties' relative intent, knowledge, access to information and opportunity to
correct or prevent such statement or omission.

         The Company, the Guarantors and the Initial Purchasers agree that it
would not be just and equitable if contributions pursuant to the immediately
preceding paragraph of this Section 6 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 immediately preceding paragraph. The amount
paid or payable by an Indemnified Person as a result of the losses, claims,
damages or liabilities (or actions or proceedings in respect thereof) referred
to in the immediately preceding paragraph shall be deemed to include any legal
or other expenses reasonably incurred by such Indemnified Person in connection
with investigating or defending any such action or claim or enforcing any rights
hereunder. Notwithstanding the provisions of this paragraph and the immediately
preceding paragraph of this Section 6, (i) in no event shall any Holder be
required to contribute any amount in excess of the amount by which the net
proceeds received by such Holder from the offering or sale of the Registrable
Securities pursuant to a Shelf Registration Statement exceeds the amount of
damages which such Holder would have otherwise been required to pay by reason of
such untrue or alleged untrue statement or omission or alleged omission and (ii)
no Person guilty of fraudulent misrepresentation (within the meaning of

                                       17
<PAGE>
Section 11(f) of the Securities Act) shall be entitled to contribution from any
Person who was not guilty of such fraudulent misrepresentation.

         Except as otherwise provided in this Section 6, any losses, claims,
damages, liabilities or expenses for which an Indemnified Person is entitled to
indemnification or contribution under this Section 6 shall be paid by the
Indemnifying Person to the Indemnified Person as such losses, claims, damages,
liabilities or expenses are incurred (or within 30 days of presentation).

         The remedies provided for in this Section 6 are not exclusive and shall
not limit any rights or remedies that may otherwise be available to any
indemnified party at law or in equity.

         The indemnity and contribution agreements contained in this Section 6
shall remain operative and in full force and effect regardless of (i) any
termination of this Agreement, (ii) any investigation made by or on behalf of
any Holder or any Person controlling any Holder or by or on behalf of the
Company and the Guarantors, their respective officers or directors or any other
Person controlling the Company or any of the Guarantors and (iii) acceptance of
and payment for any of the Registrable Securities.

7.       Rules 144 and 144A. The Company and each Guarantor covenants that it
will file the reports required to be filed by it under the Securities Act and
the Exchange Act and the rules and regulations adopted by the SEC thereunder in
a timely manner in accordance with the requirements of the Securities Act and
the Exchange Act and, for so long as any Registrable Securities remain
outstanding, if at any time the Company or such Guarantor is not required to
file such reports, it will, upon the request of any Holder or beneficial owner
of Registrable Securities, make available such information necessary to permit
sales pursuant to Rule 144A under the Securities Act. The Company and each
Guarantor further covenants that, for so long as any Registrable Securities
remain outstanding, it will use all reasonable efforts to take such further
action as any Holder of Registrable Securities may reasonably request, all to
the extent required from time to time to enable such holder to sell Registrable
Securities without registration under the Securities Act within the limitation
of the exemptions provided by (a) Rule 144(k) and Rule 144A under the Securities
Act, as such rules may be amended from time to time, or (b) any similar rule or
regulation hereafter adopted by the SEC. Notwithstanding the foregoing, nothing
in this Section 7 shall be deemed to require the Company or any Guarantor to
register any of its securities pursuant to the Exchange Act.

8.       Underwritten Registrations.

         If any of the Registrable 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 manage the offering will be selected
by, and the underwriting arrangements with respect thereto will be approved by,
the Company; provided, however, that such investment bankers and managers and
underwriting arrangements must be reasonably satisfactory to the Holders of the
majority in Amount of Registrable Securities to be included in such offering.

         No Holder of Registrable Securities may participate in any underwritten
registration hereunder unless such Holder (a) agrees to sell such Holder's
Registrable Securities on the basis provided in any underwriting arrangements
approved by the Persons entitled hereunder to

                                       18
<PAGE>
approve such arrangements and (b) completes and executes all questionnaires,
powers of attorney, indemnities, underwriting agreements and other documents
reasonably required under the terms of such underwriting arrangements.

9.       Miscellaneous.

         (a) No Inconsistent Agreements. The Company and the Guarantors have
not, as of the date hereof, and the Company and the Guarantors shall not, after
the date of this Agreement, enter into any agreement with respect to any of
their respective securities that is inconsistent with the rights granted to the
Holders of Registrable Securities in this Agreement or otherwise conflicts with
the provisions hereof.

         (b) Adjustments Affecting Registrable Securities. The Company and the
Guarantors shall not, directly or indirectly, take any action with respect to
the Registrable Securities as a class that would adversely affect the ability of
the Holders of Registrable Securities to include such Registrable Securities in
a registration undertaken pursuant to this Agreement.

         (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, otherwise than with the prior written
consent of the Company, the Guarantors and the Holders of not less than the
majority in Amount of Registrable Securities; provided, however, that Section 6
and this Section 9(c) may not be amended, modified or supplemented without the
prior written consent of the Company, the Guarantors and each Holder (including,
in the case of an amendment, modification or supplement of Section 6, any Person
who was a Holder of Registrable Securities disposed of pursuant to any
Registration Statement). Notwithstanding the foregoing, a waiver or consent to
depart from the provisions hereof with respect to a matter that relates
exclusively to the rights of Holders of Registrable Securities whose securities
are being sold pursuant to a Registration Statement and that does not directly
or indirectly affect, impair, limit or compromise the rights of other Holders of
Registrable Securities may be given by Holders of at least a majority in Amount
of the Registrable Securities being sold by such Holders pursuant to such
Registration Statement.

         (d) Notices. All notices and other communications (including without
limitation any notices or other communications to the Trustee) provided for or
permitted hereunder shall be made in writing by hand-delivery, registered
first-class mail, next-day air courier or facsimile:

                  (i) if to a Holder of Registrable Securities, at the most
         current address of such Holder set forth on the records of the
         registrar under the Indenture, in the case of Holders of Securities,
         and the stock ledger of the Company, in the case of Holders of common
         stock of the Company, unless, in either such case, any Holder shall
         have provided notice information in a Notice and Questionnaire or any
         amendment thereto, in which case such information shall control.

                  (ii) if to the Initial Purchasers:

                                    Deutsche Bank Securities Inc.
                                    31 West 52nd Street
                                    New York, New York  10019

                                       19
<PAGE>
                                    Facsimile No.: (212) 469-2929
                                    Attention:  General Counsel

                  with copies to:

                                    Akin Gump Strauss Hauer & Feld LLP
                                    1700 Pacific Avenue, Suite 4100
                                    Dallas, Texas 75201
                                    Facsimile No.: (214) 969-4343
                                    Attention:  Seth R. Molay, P.C.

                  (iii) if to the Company or the Guarantors:

                                    Grey Wolf, Inc.
                                    10370 Richmond Avenue, Suite 600
                                    Houston, Texas 77042
                                    Facsimile No.:  (713) 435-6171
                                    Attention:  Chief Financial Officer

                  with copies to:

                                    Porter & Hedges, L.L.P.
                                    700 Louisiana St., Suite 3500
                                    Houston, Texas 77002-2764
                                    Facsimile No.: (713) 228-1331
                                    Attention:  Nick D. Nicholas

         All such notices and communications shall be deemed to have been duly
given: when delivered by hand, if personally delivered; five (5) Business Days
after being deposited in the mail, postage prepaid, if mailed; one Business Day
after being timely delivered to a next-day air courier; and when the addressor
receives facsimile confirmation, if sent by facsimile during normal business
hours, and otherwise on the next Business Day during normal business hours.

         (e) Successors and Assigns. This Agreement shall inure to the benefit
of and be binding upon the successors and assigns of each of the parties hereto,
including the Holders; provided, however, that this Agreement shall not inure to
the benefit of or be binding upon a successor or assign of a Holder unless and
except to the extent such successor or assign holds Registrable Securities.

         (f) 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.

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

                                       20
<PAGE>
         (h) Governing Law. THIS AGREEMENT SHALL BE GOVERNED BY AND CONSTRUED IN
ACCORDANCE WITH THE LAWS OF THE STATE OF NEW YORK, AS APPLIED TO CONTRACTS MADE
AND PERFORMED WHOLLY WITHIN THE STATE OF NEW YORK, WITHOUT REGARD TO PRINCIPLES
OF CONFLICTS OF LAW. EACH OF THE PARTIES HERETO AGREES TO SUBMIT TO THE
JURISDICTION OF THE FEDERAL AND NEW YORK STATE COURTS SITTING IN MANHATTAN, NEW
YORK CITY, THE STATE OF NEW YORK, IN ANY ACTION OR PROCEEDING ARISING OUT OF OR
RELATING TO THIS AGREEMENT.

         (i) Severability. If any term, provision, covenant or restriction of
this Agreement is held by a court of competent jurisdiction to be invalid,
illegal, void or unenforceable, the remainder of the terms, provisions,
covenants and restrictions set forth herein shall remain in full force and
effect and shall in no way be affected, impaired or invalidated, and the parties
hereto shall use their best efforts to find and employ an alternative means to
achieve the same or substantially the same result as that contemplated by such
term, provision, covenant or restriction. It is hereby stipulated and declared
to be the intention of the parties that they would have executed the remaining
terms, provisions, covenants and restrictions without including any of such that
may be hereafter declared invalid, illegal, void or unenforceable.

         (j) Securities Held by the Company or Its Affiliates. Whenever the
consent or approval of Holders of a specified percentage in Amount of
Registrable Securities is required hereunder, Registrable Securities held by the
Company or its affiliates (as such term is defined in Rule 405 under the
Securities Act) shall not be counted in determining whether such consent or
approval was given by the Holders of such required percentage.

         (k) Third-Party Beneficiaries. Holders of Registrable Securities are
intended third party beneficiaries of this Agreement and this Agreement may be
enforced by such Persons.

         (l) Entire Agreement. This Agreement, together with the Purchase
Agreement and the Indenture, is intended by the parties as a final and exclusive
statement of the agreement and understanding of the parties hereto in respect of
the subject matter contained herein and therein and any and all prior oral or
written agreements, representations, or warranties, contracts, understandings,
correspondence, conversations and memoranda between the Initial Purchasers on
the one hand and the Company and the Guarantors on the other, or between or
among any agents, representatives, parents, subsidiaries, affiliates,
predecessors in interest or successors in interest with respect to the subject
matter hereof and thereof are merged herein and replaced hereby.




                                       21
<PAGE>
         IN WITNESS WHEREOF, the parties have executed this Registration Rights
Agreement as of the date first written above.

                                                     GREY WOLF INC.


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Executive Vice
                                           President and Chief Financial Officer


                                       GREY WOLF DRILLING COMPANY L.P.

                                           BY: GREY WOLF HOLDINGS COMPANY,
                                               ITS SOLE GENERAL PARTNER


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Executive Vice
                                           President and Chief Financial Officer


                                       GREY WOLF LLC

                                           BY: GREY WOLF HOLDINGS COMPANY,
                                               ITS SOLE MEMBER


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Executive Vice
                                           President and Chief Financial Officer


                                       GREY WOLF HOLDINGS COMPANY


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Executive Vice
                                           President and Chief Financial Officer


                                       MURCO DRILLING CORPORATION


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Executive Vice
                                           President and Chief Financial Officer


               [Signature Page to Registration Rights Agreement]

<PAGE>
                                       GREY WOLF INTERNATIONAL, INC.


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Executive Vice
                                           President and Chief Financial Officer


                                       DI/PERFENSA INC.


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Executive Vice
                                           President and Chief Financial Officer


                                       DI ENERGY, INC.


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Executive Vice
                                           President and Chief Financial Officer


                                       GREY WOLF MEXICO HOLDINGS LLC


                                       By:
                                           -------------------------------------
                                           David W. Wehlmann, Manager










               [Signature Page to Registration Rights Agreement]

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

                                       DEUTSCHE BANK SECURITIES INC.
                                       CREDIT SUISSE FIRST BOSTON LLC

                                       By:  DEUTSCHE BANK SECURITIES INC.


                                       By:
                                          --------------------------------------
                                       Name:
                                            ------------------------------------
                                                    Authorized Officer

                                       By:
                                          --------------------------------------
                                       Name:
                                            ------------------------------------
                                                    Authorized Officer


<PAGE>


                                   SCHEDULE A


                         Grey Wolf Drilling Company L.P.

                                  Grey Wolf LLC

                           Grey Wolf Holdings Company

                           Murco Drilling Corporation

                          Grey Wolf Mexico Holdings LLC

                          Grey Wolf International, Inc.

                                D/I Perfensa Inc.

                                 DI Energy, Inc.







                                       A-1