Document:

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                                                                     EXHIBIT 4.2

                          REGISTRATION RIGHTS AGREEMENT

                  REGISTRATION RIGHTS AGREEMENT (this "Agreement"), dated as of
March 28, 2002, is by and among Bill Barrett Corporation, a Maryland corporation
(the "Company"), and each of the parties listed on Annex A (the "Stockholders").

                  Whereas, the Stockholders have requested, and the Company has
agreed to provide, registration rights with respect to the Registrable
Securities (as hereinafter defined), as set forth in this Agreement.

                  Now, therefore, for and in consideration of the mutual
agreements contained herein and for other good and valuable consideration, the
receipt and sufficiency of which is hereby acknowledged, the parties hereto,
intending to be legally bound hereby, agree as follows:

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

                  "Affiliate" shall mean, when used with respect to a specified
Person, any Person which (a) directly or indirectly controls, is controlled by
or is under common control with such specified Person, (b) is an officer,
director, partner, trustee or manager of such Person, or of a Person described
in clause (a) of this sentence, or (c) is a Relative of such specified Person or
of an individual described in clauses (a) or (b) of this sentence. As used in
this definition, the term "control" means possession, directly or indirectly
(through one or more intermediaries), of the power to direct or cause the
direction of management and policies of a Person through an ownership of at
least a majority of the outstanding voting interests of such Person, or through
the power to appoint, elect or direct the vote of, a majority of the members of
the governing body of such Person whether by contract, voting trust or other
agreement. "Relative" shall mean, with respect to any individual, (i) such
individual's spouse, (ii) any direct descendent, parent, grandparent, great
grandparent or sibling (in each case, whether by blood or adoption) of such
individual or such individual's spouse, and (iii) any spouse of a person
described in clause (ii) of this sentence.

                  "Approved Appraiser" shall mean a nationally recognized
investment banking firm, accounting firm or valuation firm mutually acceptable
to the Company and the holders of a majority of the outstanding shares of Series
B Preferred Stock.

                  "Common Stock" shall mean shares of the Company's Common
Stock, par value $0.001 per share.

                  "Conversion Ratio" shall have the meaning set forth in the
Articles Supplementary establishing the Series B Preferred Stock.

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                  "Current Market Price" at any date shall mean, in the event
the Common Stock is traded in the over the counter market or on a national or
regional securities exchange, the average of the daily closing prices per share
of Common Stock for thirty (30) consecutive trading days ending three trading
days before such date (as adjusted for any stock dividend, split, combination or
reclassification that took effect during such 30 trading day period). The
closing price for each day shall be the last reported sale price regular way or,
in case no such reported sale takes place on such day, the average of the last
closing bid and asked prices regular way, in either case on the principal
national securities exchange on which the Common Stock is listed or admitted to
trading, or if not listed or admitted to trading on any national securities
exchange, the closing sale price for such day reported by Nasdaq, if the Common
Stock is traded over-the-counter and quoted in the National Market System, or if
the Common Stock is so traded, but not so quoted, the average of the closing
reported bid and asked prices of the Common Stock as reported by Nasdaq or any
comparable system, or, if the Common Stock is not listed on Nasdaq or any
comparable system, the average of the closing bid and asked prices as furnished
by two members of the National Association of Securities Dealers, Inc. selected
from time to time by the Corporation for that purpose. If the Common Stock is
not publicly traded or is not traded in such manner that the quotations referred
to above are available for the period required hereunder, Current Market Price
per share of Common Stock shall be deemed to be the fair value per share of
Common Stock as determined in good faith by the Board of Directors; provided,
however, that if a majority of the Board, including a majority of the Investor
Nominees, is unable to reach a decision on the Current Market Price, the Current
Market Price shall be determined by an Approved Appraiser.

                  "Demand Notice" shall have the meaning set forth in Section 3
hereof.

                  "Demand Registration" shall have the meaning set forth in
Section 3 hereof.

                  "Exchange Act" shall mean the Securities Exchange Act of 1934,
as amended, and the rules and regulations of the SEC promulgated thereunder.

                  "Initial Public Offering" shall mean the registered public
offering of equity securities of the Company pursuant to a registration
statement that has been declared effective under the Securities Act.

                  "Losses" shall have the meaning set forth in Section 8 hereof.

                  "Person" shall mean an individual, partnership, corporation,
limited partnership, limited liability company, foreign limited liability
company, trust, estate, corporation, custodian, trustee-executor, administrator,
nominee or entity in a representative capacity.

                  "Piggyback Notice" shall have the meaning set forth in Section
4 hereof.

                  "Piggyback Registration" shall have the meaning as set forth
in Section 4 hereof.

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                  "Proceeding" shall mean an action, claim, suit, arbitration or
proceeding (including, without limitation, an investigation or partial
proceeding, such as a deposition), whether commenced or threatened.

                  "Prospectus" shall mean the prospectus included in any
Registration Statement (including, without limitation, a prospectus that
discloses 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,
with respect to the terms of the offering of any portion of the Registrable
Securities covered by such Registration Statement, 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.

                  "Qualified Holder" shall have the meaning set forth in Section
3(a) hereof.

                  "Qualified Public Offering" shall mean any firm commitment
underwritten offering by the Corporation of shares of Common Stock to the public
pursuant to an effective registration statement under the Securities Act of
1933, then in effect, or any comparable statement under any similar federal
statutes then in force (i) for which the aggregate gross proceeds to be received
by the Company from such offering (without deducting underwriting discounts,
expenses, and commissions) are at least fifty million dollars ($50,000,000),
(ii) in which each share of Series B Preferred converts pursuant to Paragraph 5
of the Articles Supplementary for the Series B Preferred Stock into shares of
Common Stock that have an aggregate value, based on the price paid by the public
in such offering, of at least $7.50, and (iii) pursuant to which the Common
Stock is listed for trading on the New York Stock Exchange or is quoted for
trading on the Nasdaq National Market system.

                  "Registrable Securities" shall mean the shares of Common Stock
issued and issuable upon conversion of outstanding shares of Series B Preferred
Stock of the Company held by the Stockholders (including any shares of Common
Stock issued or distributed by way of dividend, stock split or other
distribution in respect of such shares). As to any particular Registrable
Securities, once issued such securities shall cease to be Registrable Securities
when (i) they are sold pursuant to an effective Registration Statement under the
Securities Act, (ii) they are sold pursuant to Rule 144 (or any similar
provision then in force under the Securities Act), (iii) they shall have ceased
to be outstanding, (iv) they have been sold in a private transaction in which
the transferor's rights under this agreement are not assigned to the transferee
of the securities, or (v) they become eligible for resale pursuant to Rule
144(k) (or any similar rule then in effect under the Securities Act). No
Registrable Securities may be registered under more than one Registration
Statement at any one time.

                  "Registration Statement" shall mean any registration statement
of the Company under the Securities Act which permits the public offering of any
of the Registrable Securities pursuant to the provisions of this Agreement,
including the Prospectus, amendments and supplements to such registration
statement, including post-

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effective amendments, all exhibits and all material incorporated by reference or
deemed to be incorporated by reference in such registration statement.

                  "Rule 144" shall mean Rule 144 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" shall mean the Securities and Exchange Commission or any
successor agency having jurisdiction under the Securities Act.

                  "Securities Act" shall mean the Securities Act of 1933, as
amended, and the rules and regulations promulgated by the SEC thereunder.

                  "Series B Preferred Stock" shall mean shares of the Company's
Series B Convertible Preferred Stock, par value $0.001 per share.

                  "underwritten registration or underwritten offering" shall
mean a registration in which securities of the Company are sold to an
underwriter for reoffering to the public.

        Section 2. Holders of Registrable Securities. A Person is deemed to be
a holder of Registrable Securities whenever such Person owns Registrable
Securities or has a right to acquire such Registrable Securities through its
ownership of the Series B Preferred Stock.

        Section 3. Demand Registration.

                  (a) Requests for Registration. At any time after an Initial
Public Offering, each of the Stockholders who is the holder of more than ten
percent of the Company's then outstanding shares of Common Stock (including the
Series B Preferred Stock, determined as if such shares had been converted to
Common Stock) or shares of Common Stock (including the Series B Preferred Stock,
determined as if such shares had been converted to Common Stock) with an
aggregate value of at least $50,000,000 based on the Current Market Price of the
Common Stock (a "Qualified Holder") shall have the right by delivering a written
notice to the Company (the "Demand Notice") to require the Company to register,
pursuant to the terms of this Agreement under and in accordance with the
provisions of the Securities Act, the number of Registrable Securities requested
to be so registered pursuant to the terms of this Agreement (a "Demand
Registration"). In addition, at any time, the Stockholders holding at least 60
percent of the Registrable Securities shall have the right to deliver a Demand
Notice and to require the Company to undertake a Demand Registration, and each
of those Stockholders shall be considered Qualified Holders for purposes of this
Agreement. Following receipt of a Demand Notice for a Demand Registration, the
Company shall use its reasonable best efforts to file a Registration Statement
and cause such securities to be registered under the Securities Act promptly,
but not later than 90 days after such Demand Notice.

                  Until such time as the Company shall become eligible to use
Form S-3 for the registration under the Securities Act of any of its securities,
each Qualified

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Holder shall be entitled to a maximum of two Demand Registrations. After such
time as the Company shall become eligible to use Form S-3 for the registration
under the Securities Act of any of its securities, each Qualified Holder shall
be entitled to a maximum of five Demand Registrations, less the total number of
Demand Registrations utilized by such holder prior to such date. Notwithstanding
any other provisions of this Section 3, in no event shall more than one Demand
Registration occur during any six-month period (measured from the effective date
of the Registration Statement to the date of the next Demand Notice) or within
120 days after the effective date of a Registration Statement filed by the
Company; provided that no Demand Registration may be prohibited for such 120-day
period more often than once in a 12-month period.

                  No Demand Registration shall be deemed to have occurred for
purposes of this Section 3(a) if the Registration Statement relating thereto
does not become effective or is not maintained effective for the period required
pursuant to this Section 3(a), in which case such requesting holder of
Registrable Securities shall be entitled to an additional Demand Registration in
lieu thereof.

                  Within ten (10) days after receipt by the Company of a Demand
Notice, the Company shall give written notice (the "Notice") of such Demand
Notice to all other holders of Registrable Securities and shall, subject to the
provisions of Section 3(b) hereof, include in such registration all Registrable
Securities with respect to which the Company received written requests for
inclusion therein within ten (10) days after such Notice is given by the Company
to such holders.

                  All requests made pursuant to this Section 3 will specify the
amount of Registrable Securities to be registered and the intended methods of
disposition thereof.

                  The Company shall be required to maintain the effectiveness of
the Registration Statement with respect to any Demand Registration for a period
of at least 180 days after the effective date thereof or such shorter period in
which all Registrable Securities included in such Registration Statement have
actually been sold; provided, however, that such 180-day period shall be
extended for a period of time equal to the period the holder of Registrable
Securities refrains from selling any securities included in such registration at
the request of an underwriter of the Company or the Company pursuant to this
Agreement.

                  Notwithstanding the foregoing paragraph, if holders of a
majority of the then outstanding Registrable Securities requested to be included
in such registration pursuant to Section 3(a) request that such Demand
Registration be a "shelf" registration pursuant to Rule 415 under the Securities
Act to permit distribution to, and resale by, the partners of a holder of
Registrable Securities (a "Partner Distribution"), and the Company is then
eligible to make such a filing, the Company shall file such Demand Registration
under Rule 415 and shall keep the Registration Statement filed in respect
thereof effective for a period which shall terminate on the earlier of (i) 180
days from the date on which the SEC declares such Registration Statement
effective and (ii) the date on which all Registrable Securities covered by such
Registration Statement have been sold

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pursuant to such Registration Statement; provided, however, that such 180-day
period shall be extended for a period of time equal to the period the holder of
Registrable Securities refrains from selling any securities included in such
registration at the request of an underwriter of the Company or the Company
pursuant to this Agreement.

                  Notwithstanding anything contained herein to the contrary, the
Company hereby agrees that (i) any Demand Registration that is a "shelf"
registration pursuant to Rule 415 under the Securities Act shall contain all
language (including, without limitation, on the prospectus cover sheet, the
principal stockholders' chart and the plan of distribution) as may be requested
by a holder of Registrable Securities to allow for a Partner Distribution and
(ii) the Company shall, at the request of any holder of Registrable Securities
seeking to effect a Partner Distribution, file any prospectus supplement or
post-effective amendments and to otherwise take any action necessary to include
such language, if such language was not included in the initial Registration
Statement, or revise such language if deemed reasonably necessary by such holder
to effect such Partner Distribution

                  (b) Priority on Demand Registration. If any of the Registrable
Securities registered pursuant to a Demand Registration are to be sold in a firm
commitment underwritten offering, and the managing underwriter or underwriters
advise the holders of such securities in writing that in its view the total
number or dollar amount of Registrable Securities proposed to be sold in such
offering is such as to adversely affect the success of such offering (including,
without limitation, securities proposed to be included by other holders of
securities entitled to include securities in such Registration Statement
pursuant to incidental or piggyback registration rights), then there shall be
included in such firm commitment underwritten offering the number or dollar
amount of Registrable Securities that in the opinion of such managing
underwriter can be sold without adversely affecting such offering, and such
Registrable Securities shall be allocated pro rata among the holders of
Registrable Securities requesting such registration on the basis of the
percentage of the Registrable Securities of the Company requested to be included
in such Registration Statement by the holders of Registrable Securities that
have requested that such securities be included in the registration. In
connection with any Demand Registration to which the provisions of this
subsection (b) apply, no securities other than Registrable Securities shall be
covered by such Demand Registration except as provided in subsection (d)(ii)
hereof, and such registration shall not reduce the number of available
registrations under this Section 3 in the event that the Registration Statement
excludes more than 50% of the aggregate number of Registrable Securities that
holders requested be included.

                  (c) Postponement of Demand Registration. The Company shall be
entitled to postpone (but not more than once in any twelve month period), for a
reasonable period of time not in excess of 90 days, the filing of a Registration
Statement if the Company delivers to the holders requesting registration a
certificate signed by both the President and Chief Financial Officer of the
Company stating that, in the good faith judgment of the Board of Directors of
the Company, such registration and offering could adversely affect or interfere
with any bona fide material financing of the Company or any material transaction
under consideration by the Company or would require disclosure of

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information that has not been disclosed to the public, the premature disclosure
of which would adversely affect the Company. Such certificate shall contain a
general statement of the reasons for such postponement and an approximation of
the anticipated delay. If the Company shall so postpone the filing of a
Registration Statement, the holder who made the Demand Registration shall have
the right to withdraw the request for registration by giving written notice to
the Company within 20 days of the anticipated termination date of the
postponement period, as provided in the certificate delivered to the holders,
and in the event of such withdrawal, such request shall not be counted for
purposes of the number of Demand Registrations to which such holder is entitled
pursuant to the terms of this Agreement.

                  (d) Registration of Other Securities. Whenever the Company
shall effect a Demand Registration pursuant to this Section 3 in connection with
an underwritten offering by one or more holders of Registrable Securities, no
securities other than Registrable Securities shall be included among the
securities covered by such Demand Registration unless (i) the managing
underwriter of such offering shall have advised each holder of Registrable
Securities requesting such registration in writing that it believes that the
inclusion of such other securities would not adversely affect such offering or
(ii) the inclusion of such other securities is approved by the affirmative vote
of the holders of at least a majority of the Registrable Securities to be
included in such Demand Registration.

        Section 4. Piggyback Registration.

                  (a) Right to Piggyback. If, at any time after a Qualified
Public Offering, the Company proposes to file a registration statement under the
Securities Act with respect to an offering of Common Stock (other than a
registration statement (i) on Form S-4, Form S-8 or any successor forms thereto
or (ii) filed solely in connection with an exchange offer or any employee
benefit or dividend reinvestment plan), whether or not for its own account,
then, each such time, the Company shall give prompt written notice of such
proposed filing at least thirty (30) days before the anticipated filing date
(the "Piggyback Notice") to all of the holders of Registrable Securities. The
Piggyback Notice shall offer such holders the opportunity to include in such
registration statement the number of Registrable Securities as each such holder
may request (a "Piggyback Registration"). Subject to Section 4(b) hereof, the
Company shall include in each such Piggyback Registration all Registrable
Securities with respect to which the Company has received written requests for
inclusion therein within ten (10) days after notice has been given to the
applicable holder. The eligible holders of Registrable Securities shall be
permitted to withdraw all or part of the Registrable Securities from a Piggyback
Registration at any time prior to the effective date of such Piggyback
Registration. The Company shall not be required to maintain the effectiveness of
the Registration Statement for a Piggyback Registration beyond the earlier to
occur of (i) 120 days after the effective date thereof and (ii) consummation of
the distribution by the holders of the Registrable Securities included in such
Registration Statement.

                  (b) Priority on Piggyback Registrations. The Company shall use
reasonable efforts to cause the managing underwriter or underwriters of a
proposed

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underwritten offering to permit holders of Registrable Securities requested to
be included in the registration for such offering to include all such
Registrable Securities on the same terms and conditions as any other shares of
capital stock, if any, of the Company included therein. Notwithstanding the
foregoing, if the managing underwriter or underwriters of such underwritten
offering have informed the Company in writing that it is their good faith
opinion that the total amount of securities that such holders, the Company and
any other Persons having rights to participate in such registration, intend to
include in such offering is such as to adversely affect the success of such
offering, then the amount of securities to be offered (i) for the account of
holders of Registrable Securities and (ii) for the account of all such other
Persons (other than the Company) shall be reduced or limited pro rata among the
holders of Registrable Securities and such other Persons requesting such
registration on the basis of the percentage of the Registrable Securities or
other securities of the Company requested to be included in such Registration
Statement by such holders that have requested that such securities be included
in the registration to the extent necessary to reduce the total amount of
securities to be included in such offering to the amount recommended by such
managing underwriter or underwriters.

                  Notwithstanding anything contained herein to the contrary, the
Company hereby agrees that (i) any Piggyback Registration that is a "shelf"
registration pursuant to Rule 415 under the Securities Act shall contain all
language (including, without limitation, on the prospectus cover sheet, the
principal stockholders' chart and the plan of distribution) as may be requested
by a holder of Registrable Securities to allow for a Partner Distribution and
(ii) the Company shall, at the request of any holder of Registrable Securities
seeking to effect a Partner Distribution, file any prospectus supplement or
post-effective amendments and to otherwise take any action necessary to include
such language, if such language was not included in the initial Registration
Statement, or revise such language if deemed reasonably necessary by such holder
to effect such Partner Distribution.

        Section 5. Restrictions on Public Sale by Holders of Registrable
Securities. Each holder of Registrable Securities agrees, in connection with the
Initial Public Offering and in connection with any underwritten registration of
Registrable Securities filed pursuant to Section 3 or Section 4 hereof, if
requested (pursuant to a written notice) by the managing underwriter or
underwriters in an underwritten offering, not to effect any public sale or
distribution of any of the Company's securities (except as part of such
underwritten offering), including a sale pursuant to Rule 144, during the period
commencing on the date of the request and continuing for not more than 180 days
(with respect to the Initial Public Offering) or 120 days (with respect to any
underwritten public offering other than the Initial Public Offering) after the
effective date of the Registration Statement pursuant to which such public
offering shall be made or such lesser period as is required by the managing
underwriter, provided, however, that all officers and directors of the Company
must be subject to similar restrictions.

                  The foregoing provisions shall not apply to any holder of
Registrable Securities if such holder is prevented by applicable statute or
regulation from entering into any such agreement; provided, however, that any
such holder shall undertake in its request to participate in any such
underwritten offering, not to effect any public sale or

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distribution of the class of securities covered by such Registration Statement
(except as part of such underwritten offering) during such period unless it has
provided forty-five (45) days' prior written notice of such sale or distribution
to the managing underwriter or underwriters.

        Section 6. Registration Procedures. If and whenever the Company is
required to use its reasonable best efforts to effect the registration of any
Registrable Securities under the Securities Act as provided in Section 3 and
Section 4 hereof, the Company shall effect such registration to permit the sale
of such Registrable Securities in accordance with the intended method or methods
of disposition thereof, and pursuant thereto the Company shall cooperate in the
sale of the securities and shall, as expeditiously as possible:

                  (a) Prepare and file with the SEC a Registration Statement or
Registration Statements on such form which shall be available for the sale of
the Registrable Securities by the holders thereof in accordance with the
intended method or methods of distribution thereof (including, without
limitation, a Partner Distribution), and use its reasonable best efforts to
cause such Registration Statement to become effective and to remain effective as
provided herein; provided, however, that before filing a Registration Statement
or Prospectus or any amendments or supplements thereto (including documents that
would be incorporated or deemed to be incorporated therein by reference), the
Company shall furnish or otherwise make available to the holders of the
Registrable Securities covered by such Registration Statement, their counsel and
the managing underwriters, if any, copies of all such documents proposed to be
filed. The Company shall not file any such Registration Statement or Prospectus
or any amendments or supplements thereto (including such documents that, upon
filing, would be incorporated or deemed to be incorporated by reference therein)
with respect to a Demand Registration to which the holders of a majority of the
Registrable Securities covered by such Registration Statement, their counsel, or
the managing underwriters, if any, shall reasonably object, in writing, on a
timely basis, unless, in the opinion of the Company, such filing is necessary to
comply with applicable law.

                  (b) Prepare and file with the SEC such amendments and
post-effective amendments to each Registration Statement as may be necessary to
keep such Registration Statement continuously effective during the period
provided herein with respect to the disposition of all securities covered by
such Registration Statement; and cause the related Prospectus to be supplemented
by any Prospectus supplement as may be necessary to comply with the provisions
of the Securities Act with respect to the disposition of the securities covered
by such Registration Statement, and as so supplemented to be filed pursuant to
Rule 424 (or any similar provisions then in force) under the Securities Act.

                  (c) Notify each selling holder of Registrable Securities, its
counsel and the managing underwriters, if any, promptly, and (if requested by
any such Person) confirm such notice in writing, (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

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effective, (ii) of any request by the SEC or any other Federal or state
governmental authority for amendments or supplements to a Registration Statement
or related Prospectus or for additional information (provided, that the Company
shall not be required to notify the holders or their counsel of all "comment"
letters received by the Company from the SEC or to deliver copies of such
comment letters or the Company's responses thereto to the holders or their
counsel unless such letters request information from or about the holders),
(iii) of the issuance by the SEC of any stop order suspending the effectiveness
of a Registration Statement or the initiation of any proceedings for that
purpose, (iv) if at any time the representations and warranties of the Company
contained in any agreement (including any underwriting agreement) contemplated
by Section 6(o) below cease to be true and correct, (v) of the receipt by the
Company of any notification with respect to the suspension of the qualification
or exemption from qualification of any of the Registrable Securities for sale in
any jurisdiction, or the initiation or threatening of any proceeding for such
purpose, and (vi) of the happening of any event 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 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 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 necessary in order to make the statements therein, in light of the
circumstances under which they were made, not misleading.

                  (d) Use its reasonable best efforts to obtain the withdrawal
of any order suspending the effectiveness of a Registration Statement, or the
lifting of any suspension of the qualification (or exemption from qualification)
of any of the Registrable Securities for sale in any jurisdiction.

                  (e) If requested by the managing underwriters, if any, or the
holders of a majority of the holders of the then outstanding Registrable
Securities being sold in connection with an underwritten offering, promptly
include in a Prospectus supplement or post-effective amendment such information
as the managing underwriters, if any, and such holders may reasonably request in
order to permit the intended method of distribution of such securities and make
all required filings of such Prospectus supplement or such post-effective
amendment as soon as practicable after the Company has received such request;
provided, however, that the Company shall not be required to take any actions
under this Section 6(e) that are not, in the opinion of counsel for the Company,
in compliance with applicable law.

                  (f) Furnish to each selling holder of Registrable Securities,
its counsel and each managing underwriter, if any, without charge, at least one
conformed copy of the Registration Statement, the Prospectus and Prospectus
supplements, if applicable, and each post-effective amendment thereto, including
financial statements (but excluding schedules, all documents incorporated or
deemed to be incorporated therein by reference, and all exhibits, unless
requested in writing by such holder, counsel or underwriter).

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                  (g) Deliver to each selling holder of Registrable Securities,
its counsel, and the underwriters, if any, without charge, as many copies of the
Prospectus or Prospectuses (including each form of Prospectus) and each
amendment or supplement thereto as such Persons may reasonably request in
connection with the distribution of the Registrable Securities; and the Company,
subject to the last paragraph of this Section 6, hereby consents to the use of
such Prospectus and each amendment or supplement thereto by each of the selling
holders of Registrable Securities and the underwriters, if any, in connection
with the offering and sale of the Registrable Securities covered by such
Prospectus and any such amendment or supplement thereto.

                  (h) Prior to any public offering of Registrable Securities,
use its reasonable best efforts to register or qualify or cooperate with the
selling holders of Registrable Securities, the 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 for offer and sale under the securities or "Blue Sky" laws of such
jurisdictions within the United States as any seller or underwriter reasonably
requests in writing and to keep each such registration or qualification (or
exemption therefrom) effective during the period such Registration Statement is
required to be kept effective and to take any other action that may be necessary
or advisable to enable such holders of Registrable Securities to consummate the
disposition of such Registrable Securities in such jurisdiction; provided,
however, that the Company will 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 that would subject it to general service of process in any such
jurisdiction where it is not then so subject.

                  (i) Cooperate with the selling holders of Registrable
Securities and the managing underwriters, if any, to facilitate the timely
preparation and delivery of certificates (not bearing any legends) representing
Registrable Securities to be sold after receiving written representations from
each holder of such Registrable Securities that the Registrable Securities
represented by the certificates so delivered by such holder will be transferred
in accordance with the Registration Statement, and enable such Registrable
Securities to be in such denominations and registered in such names as the
managing underwriters, if any, or holders may request at least two (2) business
days prior to any sale of Registrable Securities in a firm commitment public
offering, but in any other such sale, within ten (10) business days prior to
having to issue the securities.

                  (j) Use its reasonable best efforts to cause the Registrable
Securities covered by the Registration Statement to be registered with or
approved by such other governmental agencies or authorities within the United
States, except as may be required solely as a consequence of the nature of such
selling holder's business, in which case the Company will cooperate in all
reasonable respects with the filing of such Registration Statement and the
granting of such approvals, as may be necessary to enable the seller or sellers
thereof or the underwriters, if any, to consummate the disposition of such
Registrable Securities.

                  (k) Upon the occurrence of any event contemplated by Section
6(c)(vi) above, prepare a supplement or post-effective amendment to the
Registration

                                       11
<PAGE>

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, 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 light of the
circumstances under which they were made, not misleading.

                  (l) Prior to the effective date of the Registration Statement
relating to the Registrable Securities, provide a CUSIP number for the
Registrable Securities.

                  (m) Provide and cause to be maintained a transfer agent and
registrar for all Registrable Securities covered by such Registration Statement
from and after a date not later than the effective date of such Registration
Statement.

                  (n) Use its reasonable best efforts to cause all shares of
Registrable Securities covered by such Registration Statement to be authorized
to be quoted on the Nasdaq National Market or listed on a national securities
exchange if shares of the particular class of Registrable Securities are at that
time quoted on the Nasdaq National Market or listed on such exchange, as the
case may be.

                  (o) Enter into such agreements (including an underwriting
agreement in form, scope and substance as is customary in underwritten
offerings) and take all such other actions reasonably requested by the holders
of a majority of the Registrable Securities being sold in connection therewith
(including those reasonably requested by the managing underwriters, if any) to
expedite or facilitate the disposition of such Registrable Securities, and in
such connection, whether or not an underwriting agreement is entered into and
whether or not the registration is an underwritten registration, (i) make such
representations and warranties to the holders of such Registrable Securities and
the underwriters, if any, with respect to the business of the Company and its
subsidiaries, and the Registration Statement, Prospectus and documents, if any,
incorporated or deemed to be incorporated by reference therein, in each case, in
form, substance and scope as are customarily made by issuers to underwriters in
underwritten offerings, and, if true, confirm the same if and when requested,
(ii) use its reasonable best efforts to furnish to the selling holders of such
Registrable Securities opinions of counsel to the Company and updates thereof
(which counsel and opinions (in form, scope and substance) shall be reasonably
satisfactory to the managing underwriters, if any, and counsels to the selling
holders of the Registrable Securities), addressed to each selling holder of
Registrable Securities and each of the underwriters, if any, covering the
matters customarily covered in opinions requested in underwritten offerings and
such other matters as may be reasonably requested by such counsel and
underwriters, (iii) use its reasonable best efforts to obtain "cold comfort"
letters and updates thereof 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 in the Registration Statement) who have certified the

                                       12
<PAGE>

financial statements included in such Registration Statement, addressed to each
selling holder of Registrable Securities (unless such accountants shall be
prohibited from so addressing such letters by applicable standards of the
accounting profession) and each of the underwriters, if any, such letters to be
in customary form and covering matters of the type customarily covered in "cold
comfort" letters in connection with underwritten offerings, (iv) if an
underwriting agreement is entered into, the same shall contain indemnification
provisions and procedures substantially to the effect set forth in Section 8
hereof with respect to all parties to be indemnified pursuant to said Section
and (v) deliver such documents and certificates as may be reasonably requested
by the holders of a majority of the Registrable Securities being sold, their
counsel and the managing underwriters, if any, to evidence the continued
validity of the representations and warranties made pursuant to Section 6(o)(i)
above and to evidence compliance with any customary conditions contained in the
underwriting agreement or other agreement entered into by the Company. The above
shall be done at each closing under such underwriting or similar agreement, or
as and to the extent required thereunder.

                  (p) Make available for inspection by a representative of the
selling holders of Registrable Securities, any underwriter participating in any
such disposition of Registrable Securities, if any, and any attorneys or
accountants retained by such selling holders or underwriter, at the offices
where normally kept, during reasonable business hours, all financial and other
records, pertinent corporate documents and properties of the Company and its
subsidiaries, and cause the officers, directors and employees of the Company and
its subsidiaries to supply all information in each case reasonably requested by
any such representative, underwriter, attorney or accountant in connection with
such Registration Statement; provided, however, that any information that is not
generally publicly available at the time of delivery of such information shall
be kept confidential by such Persons unless (i) disclosure of such information
is required by court or administrative order, (ii) disclosure of such
information, in the opinion of counsel to such Person, is required by law, or
(iii) such information becomes generally available to the public other than as a
result of a disclosure or failure to safeguard by such Person. In the case of a
proposed disclosure pursuant to (i) or (ii) above, such Person shall be required
to give the Company written notice of the proposed disclosure prior to such
disclosure and, if requested by the Company, assist the Company in seeking to
prevent or limit the proposed disclosure. Without limiting the foregoing, no
such information shall be used by such Person as the basis for any market
transactions in securities of the Company or its subsidiaries in violation of
law.

                  (q) Comply with all applicable rules and regulations of the
SEC and make 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 forty-five
(45) days after the end of any twelve (12) month period (or ninety (90) days
after the end of any twelve (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

                                       13
<PAGE>

Registration Statement, which statements shall cover one of said twelve (12)
month periods.

                  (r) Cause its officers to use their reasonable best efforts to
support the marketing of the Registrable Securities covered by the Registration
Statement (including, without limitation, participation in "road shows") taking
into account the Company's business needs.

            The Company may require each seller of Registrable Securities as to
which any registration is being effected to furnish to the Company in writing
such information required in connection with such registration regarding such
seller and the distribution of such Registrable Securities as the Company may,
from time to time, reasonably request in writing and the Company may exclude
from such registration the Registrable Securities of any seller who unreasonably
fails to furnish such information within a reasonable time after receiving such
request.

            Each holder of Registrable Securities agrees if such holder has
Registrable Securities covered by such Registration Statement that, upon receipt
of any notice from the Company of the happening of any event of the kind
described in Section 6(c)(ii), 6(c)(iii), 6(c)(v) or 6(c)(vi) 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
6(k) hereof, or until it is advised in writing by the Company that the use of
the applicable Prospectus may be resumed, and has received copies of any
additional or supplemental filings that are incorporated or deemed to be
incorporated by reference in such Prospectus; provided, however that the Company
shall extend the time periods under Section 3 with respect to the length of time
that the effectiveness of a Registration Statement must be maintained by the
amount of time the holder is required to discontinue disposition of such
securities.

        Section 7. Registration Expenses. All reasonable fees and expenses
incident to the performance of or compliance with this Agreement by the Company
(including, without limitation, (i) all registration and filing fees (including,
without limitation, fees and expenses (A) with respect to filings required to be
made with the National Association of Securities Dealers, Inc. and (B) of
compliance with securities or Blue Sky laws, including, without limitation, any
fees and disbursements of counsel for the underwriters in connection with Blue
Sky qualifications of the Registrable Securities pursuant to Section 6(h)), (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 underwriters, if any, or by the
holders of a majority of the Registrable Securities included in any Registration
Statement), (iii) messenger, telephone and delivery expenses of the Company,
(iv) fees and disbursements of counsel for the Company, (v) expenses of the
Company incurred in connection with any road show, (vi) fees and disbursements
of all independent certified public accountants referred to in Section 6(o)(iii)
hereof (including, without limitation, the expenses of any "cold comfort"
letters required by this Agreement) and any other persons, including special
experts

                                       14
<PAGE>

retained by the Company, and (vii) fees and disbursements of one counsel for the
holders of Registrable Securities whose shares are included in a Registration
Statement) shall be borne by the Company whether or not any of the Registration
Statements is filed or becomes effective. In addition, the Company shall pay its
internal expenses (including, without limitation, all salaries and expenses of
its officers and employees performing legal or accounting duties), the expense
of any annual audit, the fees and expenses incurred in connection with the
listing of the securities to be registered on any securities exchange on which
similar securities issued by the Company are then listed and rating agency fees
and the fees and expenses of any Person, including special experts, retained by
the Company.

            The Company shall not be required to pay (i) fees and disbursements
of any counsel retained by any holder of Registrable Securities or by any
underwriter (except as set forth in clauses 7(i)(B) and 7(vii)), (ii) any
underwriter's fees (including discounts, commissions or fees of underwriters,
selling brokers, dealer managers or similar securities industry professionals)
relating to the distribution of the Registrable Securities, or (iii) any other
expenses of the holders of Registrable Securities not specifically required to
be paid by the Company pursuant to the first paragraph of this Section 7.

        Section 8. Indemnification.

                  (a) Indemnification by the Company. The Company shall, without
limitation as to time, indemnify and hold harmless, to the fullest extent
permitted by law, each holder of Registrable Securities whose Registrable
Securities are covered by a Registration Statement or Prospectus, the officers,
directors, accountants, agents and employees of each of them, each Person who
controls each such holder (within the meaning of Section 15 of the Securities
Act or Section 20 of the Exchange Act) and the officers, directors, accountants,
agents and employees of each such controlling person, each underwriter, if any,
and each person who controls (within the meaning of Section 15 of the Securities
Act or Section 20 of the Exchange Act) such underwriter, from and against any
and all losses, claims, damages, liabilities, costs (including, without
limitation, costs of preparation and reasonable attorneys' fees and any legal or
other fees or expenses incurred by such party in connection with any
investigation or Proceeding), expenses, judgments, fines, penalties, charges and
amounts paid in settlement (collectively, "Losses"), as incurred, arising out of
or based upon any untrue statement (or alleged untrue statement) of a material
fact contained in any prospectus, offering circular, or other document
(including any related registration statement, notification, or the like)
incident to any such registration, qualification, or compliance, or based on any
omission (or alleged omission) to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading, or
any violation by the Company of the Securities Act or any rule or regulation
thereunder applicable to the Company and relating to action or inaction required
of the Company in connection with any such registration, qualification, or
compliance, and will reimburse each such holder, each of its officers,
directors, partners, legal counsel, and accountants and each person controlling
such holder, each such underwriter, and each person who controls any such
underwriter, for any legal and any other expenses reasonably incurred in
connection with

                                       15
<PAGE>

investigating and defending or settling any such claim, loss, damage, liability,
or action, provided that the Company will not be liable in any such case to the
extent that any such claim, loss, damage, liability, or expense arises out of or
is based on any untrue statement or omission by such holder or underwriter, but
only to the extent, that such untrue statement (or alleged untrue statement) or
omission (or alleged omission) is made in such registration statement,
prospectus, offering circular, or other document in reliance upon and in
conformity with written information furnished to the Company by such holder. It
is agreed that the indemnity agreement contained in this Section 8(a) shall not
apply to amounts paid in settlement of any such loss, claim, damage, liability,
or action if such settlement is effected without the consent of the Company
(which consent shall not be unreasonably withheld).

                  (b) Indemnification by Holder of Registrable Securities. In
connection with any Registration Statement in which a holder of Registrable
Securities is participating, such holder of Registrable Securities shall furnish
to the Company in writing such information as the Company reasonably requests
for use in connection with any Registration Statement or Prospectus and agrees
to indemnify, to the fullest extent permitted by law, severally and not jointly,
the Company, its directors, officers, accountants, agents and employees, each
Person who controls the Company (within the meaning of Section 15 of the
Securities Act and Section 20 of the Exchange Act), and the directors, officers,
agents or employees of such controlling persons, and each underwriter, if any,
and each person who controls such underwriter (within the meaning of Section 15
of the Securities Act and Section 20 of the Exchange Act), from and against all
Losses arising out of or based on any untrue statement of a material fact
contained in any such registration statement, prospectus, offering circular, or
other document, or any omission to state therein a material fact required to be
stated therein or necessary to make the statements therein not misleading, and
will reimburse the Company and such directors, officers, partners, legal
counsel, and accountants, persons, underwriters, or control persons for any
legal or any other expenses reasonably incurred in connection with investigating
or defending any such claim, loss, damage, liability, or action, in each case to
the extent, but only to the extent, that such untrue statement or omission is
made in such registration statement, prospectus, offering circular, or other
document in reliance upon and in conformity with written information furnished
to the Company by such holder specifically for use in connection with the
preparation of such registration statement, prospectus, offering circular or
other document provided, however, that the obligations of such holder hereunder
shall not apply to amounts paid in settlement of any such claims, losses,
damages, or liabilities (or actions in respect thereof) if such settlement is
effected without the consent of such holder (which consent shall not be
unreasonably withheld); and provided, further, that the liability of each
selling holder of Registrable Securities hereunder shall be limited to the net
proceeds received by such selling holder from the sale of Registrable Securities
covered by such Registration Statement. In addition, insofar as the foregoing
indemnity relates to any such untrue statement or omission made in the
preliminary prospectus but eliminated or remedied in the amended prospectus on
file with the SEC at the time the registration statement becomes effective or in
the final prospectus filed pursuant to applicable rules of the SEC or in any
supplement or addendum thereto and such new prospectus is delivered to the
underwriter, the indemnity agreement herein shall not inure to the benefit of
such

                                       16
<PAGE>

underwriter, any controlling person of such underwriter and their respective
Representatives, if a copy of the final prospectus filed pursuant to such rules,
together with all supplements and addenda thereto was not furnished to the
person or entity asserting the loss, liability, claim or damage at or prior to
the time such furnishing is required by the Securities Act.

                  (c) Conduct of Indemnification Proceedings. If any Person
shall be entitled to indemnity hereunder (an "indemnified party"), such
indemnified party shall give prompt notice to the party from which such
indemnity is sought (the "indemnifying party") of any claim or of the
commencement of any Proceeding with respect to which such indemnified party
seeks indemnification or contribution pursuant hereto; provided, however, that
the delay or failure to so notify the indemnifying party shall not relieve the
indemnifying party from any obligation or liability except to the extent that
the indemnifying party has been prejudiced by such delay or failure. The
indemnifying party shall have the right, exercisable by giving written notice to
an indemnified party promptly after the receipt of written notice from such
indemnified party of such claim or Proceeding, to, unless in the indemnified
party's reasonable judgment a conflict of interest between such indemnified and
indemnifying parties may exist in respect of such claim, assume, at the
indemnifying party's expense, the defense of any such claim or Proceeding, with
counsel reasonably satisfactory to such indemnified party; provided, however,
that an indemnified party shall have the right to employ separate counsel in any
such claim or Proceeding and to participate in the defense thereof, but the fees
and expenses of such counsel shall be at the expense of such indemnified party
unless: (i) the indemnifying party agrees to pay such fees and expenses; or (ii)
the indemnifying party fails promptly to assume the defense of such claim or
Proceeding or fails to employ counsel reasonably satisfactory to such
indemnified party; in which case the indemnified party shall have the right to
employ counsel and to assume the defense of such claim or proceeding; provided,
however, that the indemnifying party shall not, in connection with any one such
claim or Proceeding or separate but substantially similar or related claims or
Proceedings in the same jurisdiction, arising out of the same general
allegations or circumstances, be liable for the fees and expenses of more than
one firm of attorneys (together with appropriate local counsel) at any time for
all of the indemnified parties, or for fees and expenses that are not
reasonable. Whether or not such defense is assumed by the indemnifying party,
such indemnified party will not be subject to any liability for any settlement
made without its consent (but such consent will not be unreasonably withheld).
The indemnifying party shall not consent to entry of any judgment or enter into
any settlement that does not include as an unconditional term thereof the giving
by the claimant or plaintiff to such indemnified party of a release, in form and
substance reasonably satisfactory to the indemnified party, from all liability
in respect of such claim or litigation for which such indemnified party would be
entitled to indemnification hereunder.

                  (d) Contribution. If the indemnification provided for in this
Section 8 is unavailable to an indemnified party in respect of any Losses (other
than in accordance with its terms), then each applicable indemnifying party, in
lieu of indemnifying such indemnified party, shall contribute to the amount paid
or payable by such indemnified party as a result of such Losses, in such
proportion as is appropriate to

                                       17
<PAGE>

reflect the relative fault of the indemnifying party, on the one hand, and such
indemnified party, on the other hand, in connection with the actions, statements
or omissions that resulted in such Losses as well as any other relevant
equitable considerations. The relative fault of such indemnifying party, on the
one hand, and indemnified party, on the other hand, shall be determined by
reference to, among other things, whether any action in question, including any
untrue or alleged untrue statement of a material fact or omission or alleged
omission to state a material fact, has been taken by, or relates to information
supplied by, such indemnifying party or indemnified party, and the parties'
relative intent, knowledge, access to information and opportunity to correct or
prevent any such action, statement or omission.

            The parties hereto agree that it would not be just and equitable if
contribution pursuant to this Section 8(d) were determined by pro rata
allocation or by any other method of allocation that does not take account of
the equitable considerations referred to in the immediately preceding paragraph.
Notwithstanding the provisions of this Section 8(d), an indemnifying party that
is a selling holder of Registrable Securities shall not be required to
contribute any amount in excess of the amount by which the net proceeds from the
sale of the Registrable Securities sold by such indemnifying party exceeds the
amount of any damages that such indemnifying party has 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.

                  (e) Notwithstanding the foregoing, to the extent that the
provisions on indemnification and contribution contained in the underwriting
agreement entered into in connection with the underwritten public offering are
in conflict with the foregoing provisions, the provisions in the underwriting
agreement shall control.

        Section 9. Rule 144. The Company shall file the reports required to be
filed by it under the Securities Act and the Exchange Act, and will 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
limitations of the exemption provided by Rule 144. Upon the request of any
holder of Registrable Securities, the Company shall deliver to such holder a
written statement as to whether it has complied with such requirements.

        Section 10. Underwritten Registrations. If any Demand Registration is an
underwritten offering, the Company shall have the right to select the investment
banker or investment bankers and managers to administer the offering, subject to
approval by the holders of a majority of the Registrable Securities covered by
such Demand Registration, not to be unreasonably withheld. The Company shall
have the right to select the investment banker or investment bankers and
managers to administer any Piggyback Registration.

            No Person may participate in any underwritten registration hereunder
unless such Person (i) agrees to sell the Registrable Securities it desires to
have covered

                                       18
<PAGE>

by the Demand Registration on the basis provided in any underwriting
arrangements in customary form and (ii) completes and executes all
questionnaires, powers of attorney, indemnities, underwriting agreements and
other documents required under the terms of such underwriting arrangements,
provided that such Person shall not be required to make any representations or
warranties other than those related to title and ownership of shares and as to
the accuracy and completeness of statements made in a registration statement,
prospectus, offering circular, or other document in reliance upon and in
conformity with written information furnished to the Company or the managing
underwriter by such Person.

        Section 11. Limitation on Subsequent Registration Rights. From and after
the date of this Agreement, the Company shall not, without the prior written
consent of the holders of at least sixty percent (60%) of the then outstanding
Registrable Securities, enter into any agreement with any holder or prospective
holder of any securities of the Company giving such holder or prospective holder
any registration rights the terms of which are equivalent to or more favorable
than the registration rights granted to holders of Registrable Securities
hereunder, or which would reduce the amount of Registrable Securities the
holders can include in any registration filed pursuant to Section 3 hereof,
unless such rights are subordinate to those of the holders of Registrable
Securities.

        Section 12. Miscellaneous.

                  (a) Amendments and Waivers. The provisions of this Agreement,
including the provisions of this sentence, may not be amended, modified or
supplemented, and waivers or consents to departures from the provisions hereof
may not be given, unless the Company has obtained the written consent of holders
of at least a majority of the Registrable Securities; provided, however, that in
no event shall the obligations of any holder of Registrable Securities be
materially increased or the rights of any Investor be adversely affected
(without similarly adversely affecting the rights of all Investors), except upon
the written consent of such holder. 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 the rights of other holders of Registrable
Securities may be given by holders of at least a majority of the Registrable
Securities being sold by such holders pursuant to such Registration Statement.

                  (b) Notices. All notices required to be given hereunder shall
be in writing and shall be deemed to be duly given if personally delivered,
telecopied and confirmed, or mailed by certified mail, return receipt requested,
or overnight delivery service with proof of receipt maintained, at the following
address (or any other address that any such party may designate by written
notice to the other parties):

                                       19
<PAGE>

            If to the Company:

                  Bill Barrett Corporation
                  1099 18th Street, Suite 2300
                  Denver, Colorado 80202
                  Facsimile:  (303) 291-0420

            If to any Stockholder, at his address as set forth on Exhibit A of
this Agreement. Any such notice shall, if delivered personally, be deemed
received upon delivery; shall, if delivered by telecopy, be deemed received on
the first business day following confirmation; shall, if delivered by overnight
delivery service, be deemed received the first business day after being sent;
and shall, if delivered by mail, be deemed received upon the earlier of actual
receipt thereof or five business days after the date of deposit in the United
States mail.

                  (c) Successors and Assigns. This Agreement shall inure to the
benefit of the limited partners of a Stockholder who have received shares of
Registrable Securities from a Stockholder pursuant to a Partner Distribution and
shall inure to the benefit of and be binding upon the successors and assigns of
each of the parties, including without limitation and without the need for an
express assignment, subsequent holders of Registrable Securities.

                  (d) Counterparts. This Agreement may be executed in two or
more counterparts, each of which shall be deemed an original, but all of which
together shall constitute one and the same instrument.

                  (e) Headings. The section and paragraph headings contained in
this Agreement are for reference purposes only and shall not affect in any way
the meaning or interpretation of this Agreement.

                  (f) Governing Law. This agreement shall be governed by and
construed in accordance with the laws of the State of New York (without giving
effect to the choice of law principles thereof).

                  (g) 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.

                  (h) Entire Agreement. This Agreement is intended by the
parties as a final expression of their agreement, and is intended to be a
complete and exclusive statement of the agreement and understanding of the
parties hereto in respect of the

                                       20
<PAGE>

subject matter contained herein. There are no restrictions, promises, warranties
or undertakings, other than those set forth or referred to herein, with respect
to the registration rights granted by the Company with respect to Registrable
Securities. This Agreement supersedes all prior agreements and understandings
between the parties with respect to such subject matter.

                  (i) Securities Held by the Company or its Affiliates. Whenever
the consent or approval of holders of a specified percentage of Registrable
Securities is required hereunder, Registrable Securities held by the Company or
its subsidiaries shall not be counted in determining whether such consent or
approval was given by the holders of such required percentage.

                  (j) Termination. This Agreement shall terminate when no
Registrable Securities remain outstanding; provided that Sections 7 and 8 shall
survive any termination hereof.

                  (k) Specific Performance. The parties hereto recognize and
agree that money damages may be insufficient to compensate the holders of any
Registrable Securities for breaches by the Company of the terms hereof and,
consequently, that the equitable remedy of specific performance of the terms
hereof will be available in the event of any such breach.

                                       21
<PAGE>

                  IN WITNESS WHEREOF, the parties hereto have caused this
Registration Rights Agreement to be duly executed as of the date first above
written.

                                            BILL BARRETT CORPORATION

                                            By:    /s/ J. Frank Keller
                                                   -----------------------------
                                            Name:  J. Frank Keller
                                            Title: Chief Operating Officer

                 Signature Page to Registration Rights Agreement

<PAGE>

                                        COLORADO PUBLIC EMPLOYEE
                                        RETIREMENT ASSOCIATION

                                        By:   /s/ Norman Benedict
                                              ----------------------------------
                                              Norman Benedict
                                              Deputy Executive Director of
                                              Investments

                 Signature Page to Registration Rights Agreement

<PAGE>

                              GS CAPITAL PARTNERS 2000, L.P.

                              BY:      GS Advisors 2000, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              GSCP 2000 OFFSHORE BBOG HOLDING, L.P.

                              BY:      GS Capital Partners 2000 Offshore, L.P.,
                                       its General Partner

                              BY:      GS Advisors 2000, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              GSCP 2000 GMBH BBOG HOLDING, L.P.

                              BY:      GSCP 2000 GmbH BBOG Holding I,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              GS CAPITAL PARTNERS 2000 EMPLOYEE FUND, L.P.

                              BY:      GS Employee Funds 2000 GP, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                 Signature Page to Registration Rights Agreement

<PAGE>

                              STONE STREET FUND 2000, L.P.

                              BY:      Stone Street 2000, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              STONE STREET BBOG HOLDING

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              GOLDMAN SACHS DIRECT INVESTMENT FUND 2000, L.P.

                              BY:      GS Employee Funds 2000 GP, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                 Signature Page to Registration Rights Agreement
<PAGE>

                              J.P. MORGAN PARTNERS (BHCA), L.P.

                              BY:      JPMP MASTER FUND MANAGER, L.P.,
                                       ITS GENERAL PARTNER

                              BY:      JPMP CAPITAL CORP.,
                                       ITS GENERAL PARTNER

                              By:      /s/ Christopher Behrens
                                       -----------------------------------------
                                       Christopher Behrens
                                       Managing Director

                 Signature Page to Registration Rights Agreement
<PAGE>

                              PALANTIR PARTNERS LP

                              BY:      PALANTIR ASSOCIATES LLC
                                       its General Partner

                              By:      /s/ Glenn Doshay
                                       -----------------------------------------
                                       Glenn Doshay
                                       President

                              THE DOSHAY FAMILY TRUST OF 1999

                              By:      /s/ Glenn Doshay
                                       -----------------------------------------
                                       Glenn Doshay
                                       Trustee

                 Signature Page to Registration Rights Agreement
<PAGE>

                              STATE FARM MUTUAL AUTOMOBILE INSURANCE COMPANY

                              By:      /s/ John Conklin
                                       -----------------------------------------
                                       John Conklin
                                       Vice President - Common Stocks

                              By:      /s/ John Elterich
                                       -----------------------------------------
                                       John Elterich
                                       Assistant Secretary

                 Signature Page to Registration Rights Agreement
<PAGE>

                              WARBURG PINCUS PRIVATE EQUITY VIII, L.P.

                              BY:      WARBURG PINCUS & CO.,
                                       AS GENERAL PARTNER

                              By:      /s/ Jeffrey A. Harris
                                       -----------------------------------------
                                       Jeffrey A. Harris, Partner

                 Signature Page to Registration Rights Agreement
<PAGE>

                                                                         Annex A

                                  Stockholders

Colorado Public Employee Retirement Association
1300 Logan Street
Denver, CO 80203

Goldman Sachs Direct Investment Fund 2000, L.P.
85 Broad Street
New York, NY 10004
Attention:  John Bowman

GS Capital Partners 2000, L.P.
85 Broad Street
New York, NY 10004
Attention:  John Bowman

GSCP 2000 Offshore BBOG Holding, L.P.
85 Broad Street
New York, NY 10004
Attention:  John Bowman

GSCP 2000 GmbH Holding, L.P.
85 Broad Street
New York, NY 10004
Attention:  John Bowman

GS Capital Partners 2000 Employee Fund, L.P.
85 Broad Street
New York, NY 10004
Attention:  John Bowman

J.P. Morgan Partners (BHCA), L.P.
1221 Avenue of the Americas
Floor 39
New York, NY 10020

Palantir Partners LP
c/o Tom Sullivan
Palantir Capital Inc.
153 E. 53rd Street, 43rd Floor
New York, NY 10022

<PAGE>

State Farm Mutual Automobile Insurance Company
One State Farm Plaza, E-3
Bloomington, IL 61710
Attention:  Larry Rottunda

Stone Street Fund 2000, L.P.
85 Broad Street
New York, NY 10004
Attention:  John Bowman

Stone Street BBOG Holding
85 Broad Street
New York, NY 10004
Attention:  John Bowman

The Doshay Family Trust of 1999
c/o Tom Sullivan
Palantir Capital Inc.
153 E. 53rd Street, 43rd Floor
New York, NY 10022<PAGE>
                                                                     EXHIBIT 4.3

                            BILL BARRETT CORPORATION

                             STOCKHOLDERS' AGREEMENT

                           DATED AS OF MARCH 28, 2002
                             AS AMENDED AND RESTATED
                               AS OF MARCH 4, 2004

<PAGE>

                                TABLE OF CONTENTS

<TABLE>
<CAPTION>

                                                                                                                Page

<S>                        <C>                                                                                   <C>
ARTICLE I  DEFINITIONS AND RELATED MATTERS                                                                         2
     Section 1.1           Definitions............................................................................ 2
     Section 1.2           Related Definitional Matters........................................................... 6
     Section 1.3           Capital Stock Subject To Agreement..................................................... 7

ARTICLE II STOCKHOLDERS                                                                                            7
     Section 2.1           Stockholders........................................................................... 7
     Section 2.2           Preemptive Rights For Equity Securities Issued By The Company.......................... 7

ARTICLE III RESTRICTIONS ON DISPOSITIONS OF CAPITAL STOCK                                                          9
     Section 3.1           Restrictions On Dispositions........................................................... 9
     Section 3.2           Permitted Transfers................................................................... 11
     Section 3.3           Notice Of Right Of First Refusal...................................................... 12
     Section 3.4           Rights Of First Refusal For Series A Preferred Held By Non-Management Stockholders.... 12
     Section 3.5           Rights Of First Refusal For Stock Held By Management Stockholders..................... 14
     Section 3.6           Rights Of First Refusal For Series B Preferred........................................ 15
     Section 3.7           Purchase Price........................................................................ 16
     Section 3.8           Compliance Required................................................................... 16
     Section 3.9           Certain Rights Of Inclusion........................................................... 16
     Section 3.10          Drag-Along Rights..................................................................... 17
     Section 3.11          Endorsement Of Stock Certificates..................................................... 20
     Section 3.12          Specific Performance.................................................................. 21
     Section 3.13          Government Compliance................................................................. 21

ARTICLE IV COMPANY RIGHTS AND OBLIGATIONS                                                                         21
     Section 4.1           Vesting And Repurchase Of Management Stock............................................ 21
     Section 4.2           Repurchase Option For Management Stock................................................ 23
     Section 4.3           Buyback Of Certain Shares Of Stock.................................................... 26
     Section 4.4           Financial Reports..................................................................... 27

ARTICLE V SPECIAL MANAGEMENT/GOVERNANCE PROVISIONS                                                                29
     Section 5.1           Certificate Of Incorporation:  No Conflict With Agreement............................. 29
     Section 5.2           Board Of Directors.................................................................... 29
     Section 5.3           Removal............................................................................... 32
     Section 5.4           Vacancies............................................................................. 32
     Section 5.5           Covenant To Vote...................................................................... 33
     Section 5.6           Designation Of Proxy.................................................................. 33
     Section 5.7           Investor Stockholder Rights........................................................... 33
     Section 5.8           Voting Rights......................................................................... 34
     Section 5.9           VCOC Rights........................................................................... 35
</TABLE>

                                       i
<PAGE>

<TABLE>
<S>                        <C>                                                                                   <C>
     Section 5.10          Business Opportunities................................................................ 35

ARTICLE VI MISCELLANEOUS                                                                                          36
     Section 6.1           Manner Of Giving Notice............................................................... 36
     Section 6.2           Waiver Of Notice...................................................................... 36
     Section 6.3           Counterpart Signatures................................................................ 36
     Section 6.4           Severability.......................................................................... 36
     Section 6.5           Joinder Of Spouses.................................................................... 37
     Section 6.6           Entire Agreement; Amendments; Agreement Controls...................................... 37
     Section 6.7           Governing Law And Venue............................................................... 38
     Section 6.8           Consent To Jurisdiction............................................................... 38
     Section 6.9           Binding Effect; Assignment............................................................ 38
     Section 6.10          Future Actions........................................................................ 39
     Section 6.11          Headings; Exhibits.................................................................... 39
     Section 6.12          Termination Of This Agreement......................................................... 39
     Section 6.13          Adjustments for Stock Splits, Etc..................................................... 39
     Section 6.14          Regulatory Matters.................................................................... 39

</TABLE>

                                       ii
<PAGE>
                             STOCKHOLDERS' AGREEMENT

     THIS AMENDED AND RESTATED STOCKHOLDERS' AGREEMENT (the "Agreement") is made
and entered into as of March 4, 2004 to be effective as of the 28th day of
March, 2002, among Bill Barrett Corporation, a Delaware corporation (the
"Company"), and the stockholders of the Company whose names appear on the
signature page hereto (collectively, the "Stockholders").

                                   WITNESSETH:

     WHEREAS, the Company is incorporated under the laws of the State of
Delaware with an authorized capitalization of (i) 150,000,000 shares of common
stock, par value $0.001 per share (the "Common Stock"), 8,660,148 of which are
issued and outstanding as of the date hereof, and (i) 75,000,000 shares of
Preferred Stock, par value $0.001 per share (the "Preferred Stock"), of which
6,900,000 shares have been designated the Series A Preferred Stock (the "Series
A Preferred"), 6,258,994 of which are issued and outstanding as of the date
hereof, and 52,185,000 shares have been designated the Series B Preferred Stock
(the "Series B Preferred"), 49,205,500 of which are issued and outstanding as of
the date hereof; and

     WHEREAS, certain of the Stockholders will be parties to the Stock Purchase
Agreement, among the Company and the investors listed on Annex A to such
agreement (the "Stock Purchase Agreement"), which is being executed and
delivered simultaneously with the execution and delivery by such Stockholders
and the Company of this Agreement; and

     WHEREAS, certain of the Stockholders hold shares of Common Stock are
parties to a Stockholders' Agreement, dated as of January 31, 2002, by and among
the Company and such Stockholders (the "Founders Stockholders' Agreement") and
desire to terminate the Founders Stockholders' Agreement in full; and

     WHEREAS, certain of the Stockholders hold shares of Series A Preferred
purchased pursuant to a private placement of shares as described in a
Confidential Private Placement Memorandum of the Company, dated February 11,
2002, as amended by Supplements dated February 26, 2002 and March 20, 2002, for
the offer and sale of 6,594,724 shares of Series A Preferred (the "A Round");
and

     WHEREAS, each of the Stockholders is, or will be upon consummation of the
Closing (as defined in the Stock Purchase Agreement), the owner of the number of
shares of such issued and outstanding Common Stock, Series A Preferred or Series
B Preferred of the Company set forth opposite its name on Exhibit A which shall
be amended from time to time to reflect the shares of Common Stock, Series A
Preferred and Series B Preferred owned by the Stockholders, their Permitted
Transferees and additional stockholders hereunder; and

     WHEREAS, the parties hereto deem it in their best interests and in the best
interests of the Company to set forth their respective rights and obligations in
connection with their investment in the Company; and

<PAGE>

     WHEREAS, the Board of Directors of the Company unanimously approved the
amendment of the Agreement as set forth in this Amended And Restated Agreement
and such amendment was approved by the requisite vote of the Stockholders, all
effective as of March 4, 2004; and

     WHEREAS, the parties hereto also desire to restrict the sale, assignment,
transfer, encumbrance or other disposition of the shares of Common Stock, Series
A Preferred Stock and Series B Preferred, as well as shares of capital stock
that may be issued hereafter, and to provide for certain rights and obligations
in respect thereto as hereinafter provided.

     NOW, THEREFORE, for and in consideration of the mutual agreements and
understandings set forth herein, the parties hereby agree as follows:

                                    ARTICLE I

                         DEFINITIONS AND RELATED MATTERS

         SECTION 1.1 DEFINITIONS.

         When used in this Agreement, the following terms shall have the
respective meanings set forth below:

     "AFFILIATE" shall mean, when used with respect to a specified Person, any
Person which (a) directly or indirectly controls, is controlled by or is under
common control with such specified Person, (b) is an officer, director, general
partner, trustee or manager of such Person, or of a Person described in clause
(a) of this sentence or (c) is a Relative of such specified Person or of an
individual described in clauses (a) or (b) of this sentence. As used in this
definition, the term "control" means possession, directly or indirectly (through
one or more intermediaries), of the power to direct or cause the direction of
management and policies of a Person through an ownership of at least a majority
of the outstanding voting interests of such Person, or through the power to
appoint, elect or direct the vote of, a majority of the members of the governing
body of such Person whether by contract, voting trust or other agreement.
"Relative" shall mean, with respect to any individual, (i) such individual's
spouse, (ii) any direct descendent, parent, grandparent, great grandparent or
sibling (in each case, whether by blood or adoption) of such individual or such
individual's spouse, and (iii) any spouse of a person described in clause (ii)
of this sentence.

     "A ROUND STOCKHOLDERS" shall mean the Stockholders designated as such on
Exhibit A.

     "BYLAWS" shall mean the Company's bylaws, certified by the secretary of the
Company, a copy of which is attached hereto as Exhibit C, as may be amended from
time to time.

     "CAUSE" shall mean discharge by the Company on the following grounds:

                                       2
<PAGE>

                  (i) An employee's or director's conviction or plea of nolo
     contendere in a court of law of any crime or offense, excluding traffic
     violations and other minor offenses.

                  (ii) Willful misconduct which materially adversely affects the
     reputation or business activities of the Company and which continues after
     written notice thereof from the Board of Directors of the Company to such
     employee or director stating with specificity the alleged dishonesty or
     misconduct and, if requested by the employee within 10 days thereafter,
     such employee is afforded a reasonable opportunity to be heard before the
     Board of Directors of the Company.

                  (iii) Substance abuse, including abuse of alcohol or use of
     illegal narcotics, and other drugs or substances, for which such employee
     or director fails to undertake and maintain treatment after 15 days after
     requested by the Company.

                  (iv) Misappropriation of funds or other material acts of
     dishonesty involving the Company.

                  (v) Any employee's continuing material failure or refusal to
     perform his duties or to carry out in all material respects the lawful
     directives of the Board of Directors of the Company.

     "CERTIFICATE OF INCORPORATION" shall mean the Company's Amended and
Restated Certificate of Incorporation, including all certificates of designation
with respect thereto, a copy of which is attached hereto as Exhibit B, as may be
amended from time to time.

     "CHANGE OF CONTROL" shall mean (i) a consolidation or merger involving the
Corporation, (ii) the sale, lease, or transfer of all or substantially all of
the assets of the Corporation, or (iii) any other form of corporate
reorganization in which outstanding shares of the Corporation are exchanged for
or converted into cash, securities of another corporation or business
organization (including the surviving entity of a merger), or other property,
unless, in the case of clauses (i) or (iii), the holders of a majority of the
outstanding shares of Series B Preferred Stock have consented that such
transaction shall not constitute a Change of Control.

     "CONVERSION RATIO" shall, with respect to any share of Series B Preferred,
have the meaning set forth in the Certificate of Incorporation.

     "DEFAULTING STOCKHOLDER" shall have the meaning set forth in Section 4.2(a)
of the Stock Purchase Agreement.

     "DISABILITY" shall mean a physical or mental infirmity which impairs the
Management Stockholder's ability to substantially perform his or her duties with
the Company for a period of one hundred eighty consecutive days and the
Management Stockholder has not returned to his or her full time employment prior
to the applicable date.

                                       3
<PAGE>

     "DISPOSITION" shall mean any sale, assignment, hypothecation, gift, inter
vivos transfer, pledge, hedge, mortgage or other encumbrance, or any other
disposition of capital stock of the Company whatsoever, whether voluntary or
involuntary, excluding, in the case of JPMP, any grant of a participation
interest as described in the Regulatory Sideletter.

     "EXCHANGE ACT" shall mean the Securities Exchange Act of 1934, as amended
from time to time and any successor statute thereto.

     "INITIAL PUBLIC OFFERING" shall mean the registered public offering of
equity securities of the Company pursuant to a registration statement that has
been declared effective under the Securities Act.

     "INVESTOR STOCKHOLDERS" shall mean the Stockholders designated as such on
Exhibit A.

     "JPMP" means J.P. Morgan Partners (BHCA), L.P., a Delaware limited
partnership, or its permitted successors and assigns that are Affiliates of J.P.
Morgan Partners (BHCA), L.P.

     "LIQUIDATION EVENT" shall have the meaning set forth in the Certificate of
Designations designating the Series B Preferred.

     "MANAGEMENT STOCK" shall mean all shares of Common Stock now or hereafter
owned by any of the Management Stockholders that initially were purchased from
the Company at a split adjusted price of $.04412 per share on or about January
31, 2002 and any and all securities of any kind whatsoever of the Corporation
which may be issued on or after the date hereof in respect of, in exchange for,
or upon conversion of such shares of Common Stock pursuant to a merger,
consolidation, stock split, stock dividend, recapitalization of the Corporation
or otherwise.

     "MANAGEMENT STOCKHOLDERS" shall mean the Stockholders designated as such on
Exhibit A.

     "MARKETABLE SECURITIES" shall mean freely tradable common stock (with no
restrictions on disposition under applicable law or contract) approved for
listing on the New York Stock Exchange or admitted to trading and quoted in the
Nasdaq National Market system of a corporation with a market value of its
outstanding common stock owned by non-affiliates in excess of $50,000,000.

     "NON-PARTICIPATING STOCKHOLDER" shall have the meaning set forth in Section
4.1 of the Stock Purchase Agreement.

     "ORIGINAL COST" shall mean, with respect to a particular share of capital
stock of the Company, the amount originally paid to the Company to purchase such
share.

     "PERMITTED TRANSFEREE" with respect to a transferor Stockholder means (i)
the spouse of the transferor Stockholder, (ii) a trust, or family partnership,
the sole beneficiary of which is the transferor Stockholder, the spouse of or,
any Person related by blood or adoption to,

                                       4
<PAGE>

the transferor Stockholder, or (iii) the partners, the members or stockholders
or Affiliates of an Investor Stockholder; provided that a Permitted Transferee
under this clause (iii) may not compete with the Company directly or indirectly
or engage in any aspect of the oil and gas industry other than providing
financing to or investing in businesses within such industry; provided, however,
that any such transfers contemplated by (i) through (iii) do not conflict with
or constitute a violation of state or federal securities laws. For purpose of
clause (iii) above, an Affiliate of an investor shall not be deemed to be
competing with the Company if it, through its engagement in the private equity
business, owns, directly or indirectly, interests or securities in portfolio
companies that compete with the Company or engage in any aspect of the oil and
gas industry.

     "PERSON" shall mean an individual, partnership, limited partnership,
limited liability company, foreign limited liability company, trust, estate,
corporation, custodian, trustee-executor, administrator, nominee or entity in a
representative capacity.

     "PERSONAL REPRESENTATIVE" shall mean the executor, administrator, guardian,
or other personal representative of any natural person who has become deceased
or subject to disability, or any successor or assignee thereof whether by
operation of law or otherwise.

     "PROPORTIONATE PERCENTAGE" shall mean, with respect to a Stockholder, a
fraction (expressed as a percentage) the numerator of which is the number of
shares of Common Stock, Series A Preferred and Series B Preferred held by such
Stockholder (calculated on the basis that all shares of Series B Preferred have
been converted at the Conversion Ratio, and all shares of Series A Preferred
have been converted at the "Conversion Ratio" as defined in the Certificate of
Designations for the Series A Preferred Stock) and the denominator of which is
(i) in a situation where the Proportionate Percentage is being calculated with
respect to all Stockholders, the total number of shares of Common Stock, Series
A Preferred and Series B Preferred (calculated on the basis that all shares of
Series B Preferred have been converted at the Conversion Ratio and all shares of
Series A Preferred have been converted at the "Conversion Ratio" as defined in
the Certificate of Designations for the Series A Preferred Stock) held by all
Stockholders at the time in question and (ii) in a situation where the
Proportionate Percentage is being calculated with respect to a particular group
of Stockholders, the total number of shares of Common Stock, Series A Preferred
and Series B Preferred (calculated on the basis that all shares of Series B
Preferred Stock have been converted at the Conversion Ratio and all shares of
Series A Preferred have been converted) held by the members of such group.

     "REGULATORY SIDELETTER" means the Regulatory Sideletter dated as of the
date hereof between the Company and JPMP.

     "QUALIFIED MERGER" shall mean a merger of the Company with another
corporation that is a Qualified Public Company, or a subsidiary of a Qualified
Public Company, in which the Current Market Value of the consideration received
for one share of Series B Preferred pursuant to paragraph 4 of the Certificate
of Designations for the Series B Preferred Stock is at least $7.50 per share and
which consideration consists of cash and/or Marketable Securities of such
Qualified Public Company.

                                       5
<PAGE>

     "QUALIFIED PUBLIC COMPANY" shall mean a corporation whose common stock is
authorized and approved for listing on the New York Stock Exchange or admitted
to trading and quoted in the Nasdaq National Market system and the market value
of the outstanding common stock of which corporation owned by non-affiliates of
such corporation is in excess of $50,000,000.

     "QUALIFIED PUBLIC OFFERING" shall mean any firm commitment underwritten
offering of Common Stock to the public pursuant to an effective registration
statement under the Securities Act (i) for which the aggregate gross proceeds to
the Corporation are not less than fifty million dollars ($50,000,000), (ii) in
which each share of Series B Preferred converts pursuant to paragraph 5 of the
Certificate of Designations for the Series B Preferred Stock into shares of
Common Stock that have an aggregate value, based on the price to public in such
offering, of at least $7.50 per share, and (iii) pursuant to which shares of
Common Stock are authorized and approved for listing on the New York Stock
Exchange or admitted to trading and quoted in the Nasdaq National Market system.

     "SALE OF THE COMPANY" means, in one or a series of related transactions,
sale of (i) all or substantially all the capital stock of the Company or (ii)
all or substantially all of the assets of the Company, determined on a
consolidated basis, in each case to a Person or group of Persons who are not
Affiliates of any Investor Stockholder, whether by way of merger, share
exchange, consolidation, sale of stock or assets, or otherwise.

     "SECURITIES ACT" shall mean the Securities Act of 1933, as amended from
time to time and any successor statute thereto.

     "SERIES A CONVERSION SHARES" shall mean those shares of Common Stock issued
upon conversion of the Series A Preferred.

     "SERIES B CONVERSION SHARES" shall mean those shares of Common Stock issued
upon conversion of the Series B Preferred.

     "UNVESTED SHARES" means shares of Management Stock that are not Vested
Shares.

     "VESTED SHARES" means shares of Management Stock that have become vested
pursuant to Section 4.1 hereof due to both Dollar Vesting and Time Vesting.

          SECTION 1.2 RELATED DEFINITIONAL MATTERS.

          As used in this Agreement, pronouns in masculine, feminine and neuter
genders shall be construed to include any other gender, and words in the
singular form shall be construed to include the plural and vice versa, unless
the context clearly otherwise requires. As used in this Agreement, the term
"including" shall be construed to be expansive rather than limiting in nature
and to mean "including, without limitation," except where the context clearly
otherwise requires.

                                       6
<PAGE>

          SECTION 1.3 CAPITAL STOCK SUBJECT TO AGREEMENT.

          Except as specifically provided otherwise in this Agreement, this
Agreement shall extend and apply to all shares of capital stock now owned by
each of the Stockholders and to all shares of capital stock of the Company as
may hereafter be acquired by any of the Stockholders, whether such shares
constitute the separate property or community property of any of the individual
Stockholders, and regardless of the capacity in which title to such shares is
held or taken. This Agreement shall also apply to all shares of capital stock of
the Company to which the spouse of any Stockholder is entitled by virtue of any
community property or any other laws.

                                   ARTICLE II

                                  STOCKHOLDERS

          SECTION 2.1 STOCKHOLDERS.

          The Stockholders of the Company and the number of shares of capital
stock of the Company held by each are set forth in Exhibit A as such exhibit may
be amended and updated from time to time.

          SECTION 2.2 PREEMPTIVE RIGHTS FOR EQUITY SECURITIES ISSUED BY THE
                      COMPANY.

                  (a) Except in the case of Excluded Securities (as hereinafter
defined), the Company shall not, and shall cause its subsidiaries not to, issue,
sell or exchange, agree to issue, sell or exchange, or reserve or set aside for
issuance, sale or exchange any of the equity securities of the Company or any
subsidiary of the Company (including without limitation any shares of Common
Stock, Series A Preferred or Series B Preferred, or rights to acquire any such
shares, whether or not immediately exercisable and whether evidenced by an
option, warrant, convertible security or other instrument or agreement)
(collectively, "Stock"), unless in each case the Company shall have first
offered or caused such subsidiary to offer (the "Preemptive Offer") to sell such
Stock to the Investor Stockholders (the "Offered Securities") by delivery to
such Investor Stockholders of written notice of such offer stating the Company
or subsidiary, as the case may be, proposes to sell such Offered Securities, the
number or amount of the Offered Securities proposed to be sold, the proposed
purchase price therefor and any other terms and conditions of such offer. The
Preemptive Offer shall by its terms remain open and irrevocable for a period of
20 days from the date it is delivered by the Company (the "Preemptive Offer
Period").

                  (b) Each Investor Stockholder shall have the option,
exercisable at any time during the Preemptive Offer Period by delivering written
notice to the Company (a "Preemptive Offer Acceptance Notice"), to subscribe for
(i) the number or amount of such Offered Securities up to its Proportionate
Percentage (calculated with respect to the Investor Stockholders only) of the
total number or amount of Offered Securities proposed to be issued and (ii) up
to its Proportionate Percentage (calculated with respect to the Investor
Stockholders only) of the Offered Securities not subscribed for by other
Investor Stockholders as specified in its

                                       7
<PAGE>

Preemptive Offer Acceptance Notice. Any Offered Securities not subscribed for by
an Investor Stockholder shall be deemed to be re-offered to and accepted by the
Investor Stockholders exercising their options specified in clause (ii) of the
immediately preceding sentence with respect to the lesser of (A) the amount
specified in their respective Preemptive Offer Acceptance Notices and (B) an
amount equal to their respective Proportionate Percentages (calculated with
respect to the Investor Stockholders only) with respect to such deemed offer.
Such deemed offer and acceptance procedures described in the immediately
preceding sentence shall be deemed to be repeated until either (x) all of the
Offered Securities are accepted by the Investor Stockholders or (y) no Investor
Stockholder desires to subscribe for more Offered Securities. The Company shall
notify each Investor Stockholder within five days following the expiration of
the Preemptive Offer Period of the number or amount of Offered Securities which
such Investor Stockholder has subscribed to purchase.

                  (c) If Preemptive Offer Acceptance Notices are not given by
the Investor Stockholders for all the Offered Securities, the Company shall have
45 days from the expiration of the Preemptive Offer Period to sell all or any
part of such Offered Securities as to which Preemptive Offer Acceptances Notices
have not been given by the Investor Stockholders (the "Refused Securities") to
any other Persons, but only upon terms and conditions in all material respects,
including price, which are no more favorable, in the aggregate, to such other
Persons or less favorable to the Company than those set forth in the Preemptive
Offer. Upon the closing, which shall include full payment to the Company, of the
sale to such other Persons of all the Refused Securities, the Investor
Stockholders shall purchase from the Company, and the Company shall sell to the
Investor Stockholders, the Offered Securities with respect to which Preemptive
Offer Acceptance Notices were delivered by the Investor Stockholders, at the
terms specified in the Preemptive Offer. In each case, any Offered Securities
not purchased by the Investor Stockholders or any other Persons in accordance
with this Section 2.2 may not be sold or otherwise disposed of until they are
again offered to the Investor Stockholders under the procedures specified in
this Section 2.2.

                  (d) The preemptive rights of the Investor Stockholders under
this Section 2.2 shall not apply to the following Securities (the "Excluded
Securities"):

                         (i) up to 7,850,000 shares of Common Stock issued to
     officers, employees or directors of, or consultants to, the Company or its
     subsidiaries pursuant to the terms of any stock option or similar stock
     incentive plan (including the Company's 2002 Stock Option Plan, as amended,
     and 2003 Stock Option Plan) adopted by the Board of Directors of the
     Company, including a majority of the Investor Nominees;

                         (ii) Stock issued as consideration to the sellers in
     connection with an acquisition by the Company in a bona fide arms length
     transaction, the terms of which have been approved by a majority of the
     Investor Nominees (as defined below) or Stock issued in connection with the
     transactions contemplated by that certain Letter of Intent, dated as of
     March 11, 2002 by and between the Company and the Crow Tribe and related
     letters;

                                       8
<PAGE>

                         (iii) Stock issued upon the exercise or conversion of
     any Stock issued in compliance with this Section 2.2;

                         (iv) Stock issued in a Qualified Public Offering;

                         (v) Stock issued as a stock dividend or upon any stock
     split or other pro-rata subdivision or combination of the Stock;

                         (vi) Stock issued to any Person that is not a
     Stockholder or an Affiliate of any Stockholder, so long as holders of
     shares representing 60% of the outstanding shares of Series B Preferred
     have approved the waiver of the pre-emptive rights with respect to such
     issuance;

                         (vii) Stock issued at any time after a Qualified Public
     Offering;

                         (viii) Stock held by a subsidiary of the Company which
     stock is transferred to the Company by such subsidiary;

                         (ix) Up to 455,635 shares of Series A Preferred that
     may be issued pursuant to that certain Convertible Promissory Note, dated
     as of March 27, 2002, by and between the Company and Hennie L.J.M. Gieskes;

                         (x) Shares of Series B Preferred issued pursuant to the
     Stock Purchase Agreement and shares of Common Stock issued upon the
     Conversion of those shares of Series B Preferred;

                         (xi) Up to 200,000 shares of Series B Preferred that
     may be issued pursuant to the Company's 2003 Employee Restricted Stock
     Purchase Plan and 2004 Employee Restricted Stock Purchase Plan (the
     "Purchase Plans");

                         (xii) Up to 200,000 shares of Series B Preferred that
     may be issued to Thomas B. Tyree, Jr. ("Tyree") upon the exercise of an
     option to purchase such shares for $5.00 per share until July 3, 2003
     granted to Tyree (the "Tyree Option Shares"); and

                         (xiii) Up to 50,000 shares of Series B Preferred that
     may be issued to Francis B. Barron ("Barron") upon the exercise of an
     option to purchase such shares for $5.00 per share until March 31, 2004
     granted to Barron (the "Barron Option Shares").

                                       9
<PAGE>

                                   ARTICLE III

                  RESTRICTIONS ON DISPOSITIONS OF CAPITAL STOCK

          SECTION 3.1 RESTRICTIONS ON DISPOSITIONS.

                  (a) No Stockholder, any spouse of any Stockholder, any
Personal Representative of any Stockholder, or any legal representative, agent
or assignee of any Stockholder, as the case may be, shall make any Disposition
of any shares of capital stock of the Company, except as provided in this
Article III. The parties agree that the restrictions contained in this Agreement
are fair and reasonable and in the best interests of the Company and the
Stockholders.

                  (b) Anything in this Agreement to the contrary
notwithstanding, no Disposition of capital stock of the Company otherwise
permitted or required by this Agreement shall be made unless such Disposition is
in compliance with federal and state securities laws, including without
limitation the Securities Act and the rules and regulations thereunder. If any
such Disposition is made pursuant to an exemption from such laws, rules and
regulations, such Disposition shall be made only upon the Stockholder first
having delivered to the Company a favorable written opinion of counsel,
reasonably satisfactory in form and substance to the Company, to the effect that
the proposed sale or transfer is exempt from registration under the Securities
Act and any applicable state securities laws; provided, however, that no such
opinion of counsel shall be required for (A) a transfer by a Stockholder to a
Permitted Transferee if, in each case, the Permitted Transferee agrees in
writing to be subject to the terms and conditions hereof to the same extent as
if such Permitted Transferee were an original Stockholder hereunder, or (B) a
sale duly made in compliance with Rule 144 promulgated under the Securities Act,
or any successor or analogous rule to Rule 144, or if the Stockholder would be
permitted to transfer the securities pursuant to paragraph (k) of Rule 144 (it
being agreed that the Company shall have the right to receive evidence
satisfactory to it regarding compliance with such Rule or any successor or
analogous rule prior to the registration of any such transfer), or (C) a
Disposition pursuant to an effective registration statement.

                  (c) Anything in this Agreement to the contrary
notwithstanding, unless otherwise agreed to in writing by the Company and each
of the Stockholders, no Disposition of capital stock otherwise permitted or
required by this Agreement shall be effective unless and until any transferee
who is not already a party to this Agreement (and such transferee's spouse, if
applicable) shall execute and deliver to the Company an Addendum Agreement in
the form attached hereto as Exhibit D in which such transferee (and such
transferee's spouse, if applicable) agrees to be bound by this Agreement and to
observe and comply with this Agreement and with all obligations and restrictions
imposed on Stockholders hereby; each person to whom a Disposition of capital
stock is permitted by this Agreement who receives a Disposition of capital stock
during the period when this Agreement is in effect, and who agrees in writing to
be bound by the provisions hereof, shall thereafter become a "Stockholder" for
all purposes of this Agreement. Such transferee shall become a Management
Stockholder if the transferor was a Management Stockholder or an Investor
Stockholder if the transferor was an Investor Stockholder; provided, however,
that each transferee who receives a Disposition of

                                       10
<PAGE>

capital stock that is an Affiliate of or is then (i) an Investor Stockholder,
shall become or remain an Investor Stockholder for all purposes of this
Agreement and (ii) a Management Stockholder or spouse thereof, shall become or
remain a Management Stockholder for all purposes of this Agreement.

                  (d) Dispositions of capital stock may only be made in strict
compliance with all applicable terms of this Agreement, and any purported
Disposition of capital stock that does not so comply with all applicable
provisions of this Agreement shall be null and void and of no force or effect,
and the Company shall not recognize or be bound by any such purported
Disposition and shall not effect any such purported Disposition on the stock
transfer books of the Company.

                  (e) All shares of Common Stock, Series A Preferred, and Series
B Preferred held by the Company, as treasury stock or otherwise, or any
subsidiary thereof shall not be deemed outstanding for any purpose under this
Agreement or the Bylaws of the Company.

                  (f) Prior to the consummation of an Initial Public Offering,
all newly issued shares of capital stock of the Company shall only be issued to
Persons who become party to this Agreement; provided however, that each
transferee who (i) is an employee or consultant of the Company shall become a
Management Stockholder for all purposes of this Agreement, and (ii) is not an
employee or consultant of the Company shall have such designation, if any, as
shall be determined by the Board of Directors of the Company, with the
concurrence of a majority of the Investor Nominees.

                  (g) No transfer of Management Stock or Series A Preferred or
Series B Preferred held by Management Stockholders may be made pursuant to this
Article III by a Management Stockholder prior to March 28, 2007, or such earlier
date that such Management Stockholder reaches the age of 75; provided however,
that a Management Stockholder may transfer or make a Disposition otherwise in
compliance with the provisions of this Article III with respect to an aggregate
number of shares of Series A Preferred equal to up to an aggregate of 8% of such
Management Stockholder's initial purchases of Series A Preferred in March 2002
and such Management Stockholder's aggregate purchases of Series B Preferred
initially issued pursuant to the Purchase Plan at any time on or before March
28, 2003, an aggregate of 16% of such shares on or before March 28, 2004, an
aggregate of 24% of such shares on or before March 28, 2005, an aggregate of 32%
of such shares on or before March 28, 2006, and an aggregate of 40% of such
shares on or before March 28, 2007; and further provided, however that William
J. Barrett may transfer up to 400,000 shares of Management Stock to Tyree and
John F. Keller may transfer an aggregate of 226,654 shares of Management Stock
to his children, which transfers shall not be subject to the provisions of
Sections 3.3 or 3.5 of this Agreement.

          SECTION 3.2 PERMITTED TRANSFERS.

                  (a) Subject to the provisions of Section 3.1, an A Round
Holder or its Personal Representative may at any one time prior to the time that
the Company's Common Stock is registered (an "Exchange Act Registration")
pursuant to Section 12(b) or 12(g) under the Exchange Act, or any successor
provision, transfer any or all of his or its shares of capital stock

                                       11
<PAGE>

to any person who is a Permitted Transferee with respect to the transferor
Stockholder, and such Permitted Transferee shall not be entitled to make any
transfers or Dispositions prior to Exchange Act Registration. Subject to the
provisions of Section 3.1, a Stockholder (other than an A Round Stockholder) or
his Personal Representative may at any time or times and, following Exchange Act
Registration, an A Round Holder may transfer any or all of his or its shares of
capital stock to any Person who is a Permitted Transferee with respect to the
transferor Stockholder.

                  (b) A transfer or Disposition of any kind or character
otherwise prohibited by this Agreement may be permitted if approved by the
holders of shares representing 60% or more of the outstanding shares of Series B
Preferred.

                  (c) Any transfer to a Permitted Transferee made pursuant to
this Section 3.2 shall not be subject to the terms of Sections 3.3 through 3.9
hereof.

                  (d) Notwithstanding the provisions of this Section 3.2, a
Stockholder may not make a Disposition of capital stock of the Company to a
Permitted Transferee if such Disposition has as a purpose the avoidance of
restrictions on Dispositions in this Agreement (it being understood that, solely
for such determination, at a minimum, the Permitted Transferee shall have
subsequently ceased to be a Permitted Transferee of the Stockholder that made
such Disposition to such Permitted Transferee).

          SECTION 3.3 NOTICE OF RIGHT OF FIRST REFUSAL.

          In the event that an A Round Stockholder, an Investor Stockholder or a
Management Stockholder (subject to the restrictions in Section 3.1(g)) receives
a bona fide written offer (a "Third Party Offer") for the purchase of all or a
part of his or its capital stock (or any rights or interests therein) of the
Company that such A Round Stockholder, Investor Stockholder or Management
Stockholder desires to accept, such A Round Stockholder, Investor Stockholder or
Management Stockholder (the "Offeror Stockholder") agrees to give written notice
of such Third Party Offer (the "Notice of Right of First Refusal") to the
Secretary of the Company and, within five business days after receipt of the
Notice of Right of First Refusal by the Company, the Company will send a copy of
the Notice of Right of First Refusal to the other Stockholders (the "Other
Stockholders") specified below in this Article III. The notice must set forth
the name of the proposed transferee (the "Third Party"), the number and class of
shares to be transferred (the "Offered Stock"), the price per share (the "Offer
Price"), all details of the payment terms and all other terms and conditions of
the proposed transfer. A Third Party Offer may not contain provisions related to
any property other than the capital stock of the Company held by the Offeror
Stockholder, and the Offer Price shall be expressed only in terms of cash or
credit terms contained in the proposed transfer. The Offeror Stockholder shall
deliver such Notice of Right of First Refusal to the parties noted above
promptly upon receiving such Third Party Offer, but in any event not less than
thirty (30) days prior to the date of the proposed transfer.

          The last date that the Notice of Right of First Refusal is received by
the applicable Other Stockholders shall constitute the "First Refusal Notice
Date." The Company shall be

                                       12
<PAGE>

obligated to promptly determine the First Refusal Notice Date following its
receipt of a Notice of Right of First Refusal, and such date shall be promptly
communicated in writing by the Company to all applicable Other Stockholders
within five (5) business days of the determination of such date.

          SECTION 3.4 RIGHTS OF FIRST REFUSAL FOR SERIES A PREFERRED HELD BY
                      NON-MANAGEMENT STOCKHOLDERS.

                  (a) Primary Right Of First Refusal. The Company shall have the
sole and exclusive option for a period of ten (10) days following the First
Refusal Notice Date to acquire, on the terms specified in the Notice of Right of
First Refusal, any Offered Stock that is Series A Preferred held by an Offeror
Stockholder other than a Management Stockholder. The Company may exercise such
option by giving written notice of exercise to the Offeror Stockholder and to
all Investor Stockholders prior to the termination of the Company's option
period. Such notice of exercise shall refer to the Notice of Right of First
Refusal and shall set forth the number of shares of capital stock to be acquired
by the Company and a reasonable place and time within 20 days after the date
thereof for the closing of the purchase and sale of the Offered Stock.

                  (b) Secondary Right of First Refusal. In the event that the
Company elects to purchase less than all the Offered Stock that is Series A
Preferred held by an Offeror Stockholder other than a Management Stockholder,
the Investor Stockholders shall have the exclusive option from the 11th to the
30th day following the First Refusal Notice Date to acquire all or any portion
of the Offered Stock in accordance with the provisions of the Notice of Right of
First Refusal. The Investor Stockholders may, by agreement, allocate among
themselves the right to acquire such part of the Offered Stock. In the absence
of such an agreement among the Investor Stockholders, each Investor Stockholder
will be entitled to give written notice to the Offeror Stockholder, to the
Company and to the Investor Stockholders, from the eleventh day to the twentieth
day following the First Refusal Notice Date, of such Investor Stockholder's
election ("Election Notice") to acquire all or any part of its Proportionate
Percentage (calculated solely with respect to the Investor Stockholders) of the
Offered Stock that is not being acquired by the Company or the Investor
Stockholders including a statement of the maximum number of shares of Offered
Stock that such Investor Stockholder is willing to purchase.

                  (c) Any Offered Stock not subscribed for pursuant to Section
3.4(b) by the Investor Stockholders shall be deemed to be re-offered to and
accepted by the Investor Stockholders exercising their rights to purchase
Offered Stock with respect to the lesser of (A) the amount specified in their
respective Election Notices and (B) an amount equal to their respective
Proportionate Percentages (calculated solely with respect to the Investor
Stockholders) with respect to such deemed offer. Such deemed offer and
acceptance procedures described in the immediately preceding sentence shall be
deemed to be repeated until either (x) all of the Offered Stock is accepted by
the Investor Stockholders or (y) no Investor Stockholder desires to subscribe
for more Offered Stock. The Company shall notify each Investor Stockholder
within five days following the expiration of the period described in Section
3.4(b) of the number or amount of Offered Stock which such Stockholder has
subscribed to purchase and shall set a

                                       13
<PAGE>

reasonable place and time from the date thereof for the closing of the purchase
and sale of the Offered Stock.

                  (d) If the Company and the Investor Stockholders do not
purchase all of the Offered Stock, the remaining Offered Stock (or any portion
thereof) may be sold by the Offeror Stockholder at any time within ninety (90)
days after the date of the Third Party Offer, subject to the provisions of
Section 3.1 hereof. Any such sale shall not be at less than the price or upon
terms and conditions more favorable to the purchaser than those specified in the
Third Party Offer.

          SECTION 3.5 RIGHTS OF FIRST REFUSAL FOR STOCK HELD BY MANAGEMENT
                      STOCKHOLDERS.

                  (a) Primary Right Of First Refusal. The Management
Stockholders (the "Other Management Stockholders") other than an Offeror
Stockholder that is a Management Stockholder shall have the sole and exclusive
option for a period of ten (10) days following the First Refusal Notice Date to
acquire, on the terms specified in the Notice of Right of First Refusal, any
Offered Stock held by an Offeror Stockholder that is a Management Stockholder.
The Other Management Stockholders may, by agreement, allocate among themselves
the right to acquire such part of the Offered Stock. In the absence of such an
agreement among the Other Management Stockholders, each Other Management
Stockholder will be entitled to give written notice to the Offeror Stockholder,
to the Company and to the Other Management Stockholders, on or before the
eleventh day following the First Refusal Notice Date, of such Other Management
Stockholder's election ("Election Notice") to acquire all or any part of its
Proportionate Percentage (calculated solely with respect to the Other Management
Stockholders) of the Offered Stock, including a statement of the maximum number
of shares of Offered Stock that such Other Management Stockholder is willing to
purchase. Any Offered Stock not subscribed for pursuant to this Section 3.5(a)
by the Other Management Stockholders shall be deemed to be re-offered to and
accepted by the Other Management Stockholders exercising their rights to
purchase Offered Stock with respect to the lesser of (A) the amount specified in
their respective Election Notices and (B) an amount equal to their respective
Proportionate Percentages (calculated solely with respect to the Other
Management Stockholders) with respect to such deemed offer. Such deemed offer
and acceptance procedures described in the immediately preceding sentence shall
be deemed to be repeated until either (x) all of the Offered Stock is accepted
by the Other Management Stockholders or (y) no Other Management Stockholder
desires to subscribe for more Offered Stock. The Company shall notify each Other
Management Stockholder within five days following the expiration of the period
described in this Section 3.5(a) of the number or amount of Offered Stock which
such Stockholder has subscribed to purchase and shall set a reasonable place and
time from the date thereof for the closing of the purchase and sale of the
Offered Stock.

                  (b) Secondary Right of First Refusal. In the event that the
Other Management Stockholders elect to purchase less than all the Offered Stock
pursuant to Section 3.5(a), the Investor Stockholders shall have the exclusive
option from the 11th to the 30th day following the First Refusal Notice Date to
acquire all or any portion of the Offered Stock in accordance with the
provisions of the Notice of Right of First Refusal. The Investor

                                       14
<PAGE>

Stockholders may, by agreement, allocate among themselves the right to acquire
such part of the Offered Stock. In the absence of such an agreement between the
Investor Stockholders, each Investor Stockholder will be entitled to give a
written Election Notice to the Offeror Stockholder, to the Company and to the
other Investor Stockholders, from the eleventh day to the twentieth day
following the First Refusal Notice Date, of such Investor Stockholder's election
to acquire all or any part of its Proportionate Percentage (calculated solely
with respect to the Investor Stockholders) of the Offered Stock that is not
being acquired by the Other Management Stockholders or the Investor Stockholders
including a statement of the maximum number of shares of Offered Stock that such
Investor Stockholder is willing to purchase.

                  (c) Any Offered Stock not subscribed for pursuant to Section
3.5(b) by the Investor Stockholders shall be deemed to be re-offered to and
accepted by the Investor Stockholders exercising their rights to purchase
Offered Stock with respect to the lesser of (A) the amount specified in their
respective Election Notices and (B) an amount equal to their respective
Proportionate Percentages (calculated solely with respect to the Investor
Stockholders) with respect to such deemed offer. Such deemed offer and
acceptance procedures described in the immediately preceding sentence shall be
deemed to be repeated until either (x) all of the Offered Stock is accepted by
the Investor Stockholders or (y) no Investor Stockholder desires to subscribe
for more Offered Stock. The Company shall notify each Investor Stockholder
within five days following the expiration of the period described in Section
3.5(b) of the number or amount of Offered Stock which such Stockholder has
subscribed to purchase and shall set a reasonable place and time from the date
thereof for the closing of the purchase and sale of the Offered Stock.

                  (d) If the Other Management Stockholders and the Investor
Stockholders do not purchase all of the Offered Stock, the remaining Offered
Stock (or any portion thereof) may be sold by the Offeror Stockholder at any
time within ninety (90) days after the date of the Third Party Offer, subject to
the provisions of Section 3.1 hereof. Any such sale shall not be at less than
the price or upon terms and conditions more favorable to the purchaser than
those specified in the Third Party Offer.

          SECTION 3.6 RIGHTS OF FIRST REFUSAL FOR SERIES B PREFERRED.

                  (a) Primary Right Of First Refusal. The Investor Stockholders
other than an Offeror Stockholder that is an Investor Stockholder (the "Other
Investor Stockholders") shall have the sole and exclusive option for a period of
ten (10) days following the First Refusal Notice Date to acquire, on the terms
specified in the Notice of Right of First Refusal, any Offered Stock that is
Series B Preferred held by an Offeror Stockholder that is an Investor
Stockholder. The Other Investor Stockholders may, by agreement, allocate among
themselves the right to acquire such part of the Offered Stock. In the absence
of such an agreement among the Other Investor Stockholders, each Other Investor
Stockholder will be entitled to give a written Election Notice to the Offeror
Stockholder, to the Company and to the remaining Other Investor Stockholders, on
or before the eleventh day following the First Refusal Notice Date, of such
Other Investor Stockholder's election to acquire all or any part of its
Proportionate Percentage (calculated solely with respect to the Other Investor
Stockholders) of the Offered Stock that is not being acquired by the Other
Investor Stockholders including a statement of the maximum

                                       15
<PAGE>

number of shares of Offered Stock that such Other Investor Stockholder is
willing to purchase. Any Offered Stock not subscribed for pursuant to this
Section 3.6(a) by the Other Investor Stockholders shall be deemed to be
re-offered to and accepted by the Other Investor Stockholders exercising their
rights to purchase Offered Stock with respect to the lesser of (A) the amount
specified in their respective Election Notices and (B) an amount equal to their
respective Proportionate Percentages (calculated solely with respect to the
Other Investor Stockholders) with respect to such deemed offer. Such deemed
offer and acceptance procedures described in the immediately preceding sentence
shall be deemed to be repeated until either (x) all of the Offered Stock is
accepted by the Other Investor Stockholders or (y) no Other Investor Stockholder
desires to subscribe for more Offered Stock. The Company shall notify each Other
Investor Stockholder within five days following the expiration of the period
described in this Section 3.6(a) of the number or amount of Offered Stock which
such Stockholder has subscribed to purchase and shall set a reasonable place and
time from the date thereof for the closing of the purchase and sale of the
Offered Stock.

                  (b) Secondary Right of First Refusal. In the event that the
Other Investor Stockholders elect to purchase less than all the Offered Stock
pursuant to Section 3.6(a), the Company shall have the exclusive option from the
11th to the 30th day following the First Refusal Notice Date to acquire all or
any portion of the Offered Stock in accordance with the provisions of the Notice
of Right of First Refusal by giving a written Election Notice to the Offeror
Stockholder and to the Other Investor Stockholders, from the eleventh day to the
twentieth day following the First Refusal Notice Date, of the Company's election
to acquire all or any part of the Offered Stock that is not being acquired by
the Other Investor Stockholders.

                  (c) If the Other Investor Stockholders and the Company do not
purchase all of the Offered Stock, the remaining Offered Stock (or any portion
thereof) may be sold by the Offeror Stockholder at any time within ninety (90)
days after the date of the Third Party Offer, subject to the provisions of
Section 3.1 and Section 3.9 hereof. Any such sale shall not be at less than the
price or upon terms and conditions more favorable to the purchaser than those
specified in the Third Party Offer. In the event the Third Party Offeror will
only purchase all of the Offered Stock after taking into consideration the
rights set forth in Section 3.9, the Offeror Stockholder may rescind the
Election Notices of the Investor Stockholders and the Company, if such Election
Notices are, in the aggregate, for less than all the Offered Stock.

          SECTION 3.7 PURCHASE PRICE.

          The total purchase price (the "Purchase Price") for all the capital
stock to be purchased pursuant to Section 3.4, 3.5 and/or 3.6 will be the total
purchase price for the proposed transfer, and upon the same terms and
conditions, as set forth in the Third Party Offer.

          SECTION 3.8 COMPLIANCE REQUIRED.

          Any Disposition described in Sections 3.3 through 3.7 hereof of a
Stockholder's capital stock without complying with the giving of a Notice of
Right of First Refusal and the Right of First Refusal provisions of this Article
III shall be void, and the Company shall issue a Notice of Right of First
Refusal upon discovery of such transfer, a copy of which shall be sent to

                                       16
<PAGE>

the person or entity making such transfer, his or its transferee, and the
Company. The duty of the Company to see to the issuance of such Notice of Right
of First Refusal shall not be considered to be elective, but shall be mandatory.
Upon the giving of the Notice of Right of First Refusal, the time period for the
exercise of the options specified in Sections 3.4, 3.5 and 3.6 shall commence
running.

          SECTION 3.9 CERTAIN RIGHTS OF INCLUSION.

                  (a) If all or any part of the shares of Series B Preferred
proposed to be transferred by an Investor Stockholder to a proposed transferee
have not been purchased pursuant to Section 3.6 hereof, the Offeror Stockholder
shall not, individually or collectively, in any transaction, sell or otherwise
dispose of shares of Series B Preferred held by such Stockholder to a third
party, other than to a Permitted Transferee, unless the terms and conditions of
the Third Party Offer include an offer, at the Offer Price and on the same terms
as the offer to the selling Investor Stockholders, to each of the other Investor
Stockholders (the "Offerees"), to include at the option of each Offeree, in the
sale or other disposition to the Third Party, a number of shares of Series B
Preferred owned by each Offeree determined in accordance with this Section 3.9.

                  (b) The Investor Stockholder that receives the Third Party
Offer (the "Selling Stockholder") shall cause the Third Party Offer to be
reduced to writing (which writing shall include an offer to purchase or
otherwise acquire shares of Series B Preferred from the Offerees as required by
this Section 3.9 and a time and place designated for the closing of such
purchase, which time shall not be less than 20 days after delivery of such
notice and no more than 60 days after such delivery date) and shall send written
notice of the Third Party Offer together with a copy of the Third Party Offer
(the "Inclusion Notice") to each of the Offerees in the manner specified in
Section 6.1 hereof.

                  (c) Each Offeree shall have the right (an "Inclusion Right"),
exercisable by delivery of notice to the Selling Stockholder at any time within
twenty (20) calendar days after delivery of the Inclusion Notice, to sell
pursuant to the Third Party Offer a number of such Offeree's shares of Series B
Preferred equal to his or its Proportionate Percentage (based on the shares held
by the selling Stockholder and Offerees exercising their Inclusion Rights).

                  (d) The Offerees and the Selling Stockholder shall sell to the
proposed transferee all, or at the option of the proposed transferee, any part
of the shares of Series B Preferred proposed to be transferred by them at not
less than the price and upon the terms and conditions, if any, not more
favorable to the proposed transferee than those in the Inclusion Notice at the
time and place provided for the closing in the Inclusion Notice, or at such
other time and place as the Offerees, the Selling Stockholder, and the proposed
transferee shall agree.

          SECTION 3.10 DRAG-ALONG RIGHTS.

                  (a) If the Board of Directors, including a majority of the
Investor Nominees, or holders of 70% of the outstanding shares of Series B
Preferred, votes in favor of a Sale of the Company (an "Approved Sale"), all
Stockholders shall consent to and raise no

                                       17
<PAGE>

objections against the Approved Sale, and if the Approved Sale is structured as
(A) a merger, share exchange or consolidation of the Company, or a sale of all
or substantially all of the assets of the Company, each Stockholder shall vote
in favor of the Approved Sale and shall waive any dissenters rights, appraisal
rights or similar rights in connection with such merger, consolidation or asset
sale, or (B) a sale of all the capital stock of the Company, the Stockholders
shall agree to sell all their shares of Common Stock, Series A Preferred, Series
A Conversion Shares, Series B Preferred, and Series B Conversion Shares which
are the subject of the Approved Sale, on the terms and conditions of such
Approved Sale. The Stockholders shall take all necessary and desirable actions
in connection with the consummation of the Approved Sale, including using their
reasonable best efforts to obtain Board of Directors' consent to the Approved
Sale and the execution of such agreements and such instruments and other actions
reasonably necessary to (1) provide customary representations, warranties,
indemnities, and escrow arrangements relating to such Approved Sale and (2)
effectuate the allocation and distribution of the aggregate consideration upon
the Approved Sale as set forth in Section 3.10(c) below. The Stockholders shall
be permitted to sell their shares of capital stock pursuant to an Approved Sale
without complying with any other provisions of Article III of this Agreement.

                  (b) The Investor Stockholders that have initiated an Approved
Sale pursuant to Section 3.10(a) (whether directly or through the action of
their respective Investor Nominees), shall represent and warrant, severally and
not jointly, to the other Stockholders that no direct or indirect collateral
benefit or supplemental consideration (whether or not in the nature of a
tangible or intangible asset, money, property, security or other tangible
benefits or opportunities) has been or is to be paid by such prospective
purchaser or any other person to such Investor Stockholder or its Affiliates, in
connection with the Approved Sale, and that such Approved Sale is not made as
part of or in connection with any other transaction pursuant to which such
Investor Stockholder will receive any additional benefit or consideration, based
on such Investor Stockholder's ownership of capital stock of the Company
(excluding any reasonable fees or commissions paid for consulting, advisory or
other services). The foregoing provision shall not be deemed to prohibit a sale
of the Company to any Person merely because such Person has, is currently having
or intends to have a business relationship with one or more Stockholders.

                  (c) The obligations of the Stockholders pursuant to this
Section 3.10 are subject to the satisfaction of the following conditions:

                         (i) upon the consummation of the Approved Sale, each
     Stockholder shall receive the same proportion of the aggregate
     consideration from such Approved Sale that such holder would have received
     if such aggregate consideration had been distributed by the Company in
     complete liquidation pursuant to the rights and preferences set forth in
     the Certificate of Incorporation of the Company as in effect immediately
     prior to such Approved Sale (giving effect to applicable orders of
     priority);

                         (ii) if any Stockholders of a class are given an option
     as to the form and amount of consideration to be received, all Stockholders
     will be given the same option;

                                       18
<PAGE>

                         (iii) (A) all holders of options, warrants or similar
     rights to acquire capital stock of the Company ("Stock Equivalents") that
     are then currently exercisable will be given an opportunity to exercise
     such rights prior to the consummation of the Approved Sale (but only to the
     extent such Stock Equivalents are then vested or would be vested on an
     accelerated basis pursuant to the terms of their issuance) and participate
     in such sale as Stockholders, (B) all options issued under stock options
     plans of the Company that are then vested or would be vested on an
     accelerated basis pursuant to the terms of their issuance, but have not
     been exercised prior to the consummation of the Approved Sale, will be
     cancelled and the holders thereof will be entitled to receive in
     consideration therefor, at the election of the Company in the form of cash
     or securities that are distributed to stockholders pursuant to this Section
     3.10, with a value (as determined pursuant to Section 3.10(c)(vi)) in an
     amount equal to the aggregate value of the Common Stock acquirable upon
     exercise of such options (with the value of such Common Stock being the
     value attributed to Common Stock pursuant to Section 3.10(c)(i) above) less
     the aggregate proceeds that would be payable by the option holders upon the
     exercise of all such options (without regard to any net exercise or
     cashless exercise basis), and (C) all options issued under stock option
     plans of the Company that are not then vested and would not be vested on an
     accelerated basis on the terms of their issuance will be cancelled without
     consideration;

                         (iv) no Stockholder shall be obligated to make any
     out-of-pocket expenditure prior to the consummation of the Approved Sale
     (excluding modest expenditures for postage, copies, etc.) and no
     Stockholder shall be obligated to pay any portion (or shall be entitled to
     be reimbursed by the Company for that portion paid) that is more than its
     pro rata share (based upon the amount of consideration received) of
     reasonable expenses incurred in connection with a consummated Approved
     Sale, to the extent such costs are incurred for the benefit of all
     Stockholders, and are not otherwise paid by the Company or the acquiring
     party (costs incurred by or on behalf of a Stockholder for its sole benefit
     will not be considered costs of the transaction hereunder), provided that a
     Stockholder's liability for such expenses shall be capped at the total
     purchase price received by such Stockholder for its shares of capital
     stock, plus Stock Equivalents;

                         (v) no Stockholder shall be required to provide any
     representations, warranties or indemnities (other than pursuant to an
     escrow of consideration proportionate to the amount receivable under this
     Section 3.10) in connection with the Approved Sale, other than those
     required to be made pursuant to Section 3.10(b) to other Stockholders and
     those representations, warranties and indemnities concerning each
     Stockholder's valid ownership of shares of capital stock and Stock
     Equivalents, free of all liens and encumbrances (other than those arising
     under applicable securities laws), and each Stockholder's authority, power,
     and right to enter into and consummate such purchase or merger agreement
     without violating any other agreement to which such Stockholder is a party
     or its assets are bound; and

                                       19
<PAGE>

                         (vi) if some or all of the consideration received in
     connection with the Approved Sale is other than cash, then the valuation of
     such assets shall be deemed to have a dollar value equal to the fair market
     value of such assets as determined by the unanimous resolution of all
     directors of the Board of Directors of the Company; provided that if the
     Board of Directors of the Company does not or is unable to make such a
     determination of fair market value, such determination of fair market value
     shall be made by an investment banking firm of recognized national standing
     selected by a majority of the Investor Nominees, which firm shall be
     reasonably acceptable to a majority of the directors of the Board of
     Directors of the Company, and such firm shall be engaged and paid by the
     Company. The determination of fair market value of such investment banking
     firm (or, if such investment bank determines a range of fair market values,
     the mid-point of such range) shall be final and binding on all parties.

                  (d) If the Company and any of the Stockholders or their
representatives, enter into any negotiation or transaction for which Rule 506
under the Securities Act (or any similar rule then in effect) may be available
with respect to such negotiation or transaction (including a merger,
consolidation or other reorganization), each Stockholder who is not an
accredited investor (as such term is defined in Rule 501 under the Securities
Act) will, at the request of the Company or the Investor Stockholders, appoint a
purchaser representative (as such term is defined in Rule 501 under the
Securities Act) reasonably acceptable to the Company or such Stockholders.

                  (e) The Persons initiating an Approved Sale shall have the
right to require the Company to cooperate fully with potential acquirors of the
Company in a prospective Sale of the Company by taking all customary and other
actions reasonably requested by such Persons or such potential acquirors,
including without limitation, making the Company's properties, books and
records, and other assets available for inspection by such potential acquirors
and making its employees available for interviews.

          SECTION 3.11 ENDORSEMENT OF STOCK CERTIFICATES.

                  (a) Conformed copies of this Agreement shall be filed with the
Secretary of the Company and kept with the records at its principal office. An
officer of the Company shall endorse each certificate representing the shares of
capital stock of the Company heretofore or hereafter issued by the Company to
the Stockholders by causing to be placed on the face thereof the following:

     TRANSFER IS SUBJECT TO RESTRICTIVE STOCK LEGENDS ON BACK

     and by causing to be placed on the back thereof the legend in substantially
the following form:

     THE SHARES OF STOCK REPRESENTED BY THIS CERTIFICATE ARE SUBJECT TO THE
     TERMS OF A STOCKHOLDERS' AGREEMENT DATED AS OF MARCH 28, 2002, BY AND AMONG
     THE COMPANY AND

                                       20
<PAGE>

     CERTAIN OTHER PERSONS, WHICH AGREEMENT CONTAINS, AMONG OTHER PROVISIONS,
     RESTRICTIONS ON THE TRANSFER, SALE OR OTHER DISPOSITION OF THE SHARES OF
     STOCK REPRESENTED BY THIS CERTIFICATE. A COPY OF SUCH STOCKHOLDERS'
     AGREEMENT HAS BEEN FILED, AND IS AVAILABLE FOR REVIEW BY THE RECORD HOLDER
     OF THIS CERTIFICATE, AT THE PRINCIPAL OFFICE OF THE COMPANY.

                  (b) In addition to the legend required under Section 3.11(a)
above, each Stockholder agrees that each certificate representing the shares of
capital stock of the Company heretofore or hereafter issued by the Company shall
also bear such other legends as required pursuant to the Stock Purchase
Agreement. Any such legend shall be removed by the Company upon the request
(which shall include customary representations and opinions of counsel if
reasonably requested by the Company) of a Stockholder when such legend is no
longer applicable.

          SECTION 3.12 SPECIFIC PERFORMANCE.

          Each of the parties to this Agreement acknowledges that it shall be
impossible to measure in money the damage to the Company or the Stockholder(s),
if any of them or any transferee or any legal representative of any party hereto
fails to comply with any of the restrictions or obligations imposed by this
Article III, that every such restriction and obligation is material, and that in
the event of any such failure, the Company or the Stockholder(s) shall not have
an adequate remedy at law or in damages. Therefore, each party hereto consents
to the issuance of an injunction or the enforcement of other equitable remedies
against him at the suit of an aggrieved party without the posting of any bond or
other security, to compel specific performance of all of the terms of this
Article III and to prevent any disposition of shares of capital stock in
contravention of any terms of this Article III, and waives any defenses thereto,
including, without limitation, the defenses of: (i) failure of consideration;
(ii) breach of any other provision of this Agreement; and (iii) availability of
relief in damages.

          SECTION 3.13 GOVERNMENT COMPLIANCE.

          In connection with any closing of a Disposition pursuant to this
Article III, each of the parties to this Agreement shall (i) take all steps
necessary and desirable to obtain all required third-party, governmental and
regulatory consents and approvals to facilitate the consummation of such
Disposition, and (ii) use reasonable efforts to delay any closing dates pursuant
to this Article III to the extent required to allow any party to take such
actions.

                                       21
<PAGE>

                                   ARTICLE IV

                         COMPANY RIGHTS AND OBLIGATIONS

          SECTION 4.1 VESTING AND REPURCHASE OF MANAGEMENT STOCK.

                  (a) The Company and the Management Stockholders hereby agree
to be bound by the provisions of this Section 4.1 during the term of this
Agreement notwithstanding (i) the provisions of Section 3 of the Subscription
Agreements, dated as of January 31, 2002, by and between the Company and each of
the Management Stockholders, or (ii) the provisions of the Founders
Stockholders' Agreement. The Company and the Management Stockholders hereby
agree that the Founders' Stockholders' Agreement is terminated in its entirety
as of the date hereof. Each Management Stockholder's shares of Management Stock
will become vested in accordance with the schedule set forth in this Section
4.1(a), if, as of each applicable date, the Management Stockholder is still
employed by either the Company or any of its subsidiaries (or the Management
Stockholder's employment was terminated due to death or Disability). The
Management Stock will also become vested at the rate of one share for every
$30.40549 received and accepted by the Company pursuant to the Stock Purchase
Agreement ("Dollar Vesting"). Dollar Vesting shall apply ratably over all shares
of Management Stock held by Management Stockholders based on the Proportionate
Percentage of Management Stock owned by each Management Stockholder. The
Management Stock that is not vested as a result of Dollar Vesting on or before
January 31, 2007, or the earlier occurrence of a Liquidation Event, a Qualified
Public Offering or a transaction pursuant to Section 3.10, shall be forfeited
and cancelled on the stock transfer records of the Company without payment
therefor to the holder and the holder shall immediately upon the request of the
Company after the occurrence of such an event deliver the certificates
representing those shares to the Company for cancellation. In addition to the
Dollar Vesting of the Management Stock, the Management Stock will also become
vested at the earlier to occur of the holder's having reached the age of 75 or
satisfaction of the following vesting schedule (the "Time Vesting"):

         <TABLE>
         <CAPTION>

                                                                                        % Vested
                                                                                        ---------
         <S>                                                                            <C>
         Date of Purchase (January 31, 2002)                                              20%
         First Anniversary Date of Purchase (January 31, 2003)                            40%
         Second Anniversary Date of Purchase (January 31, 2004                            60%
         Third Anniversary Date of Purchase (January 31, 2005)                            80%
         Fourth Anniversary Date of Purchase (January 31, 2006)                           100%
         </TABLE>

The Management Stock will become Vested Shares on the date on which both Dollar
Vesting and Time Vesting have occurred.

                  (b) If a Management Stockholder ceases to be employed by the
Company or any of its subsidiaries on any date other than an anniversary date of
the date of purchase, the percentage of Management Stock to become Time Vested
during the period from the most recent January 31 will be determined on a pro
rata basis for the current year according to the number of full calendar months
elapsed since the most recent January 31.

                                       22
<PAGE>

                  (c) Subject to Section 4.1(a), upon the occurrence of the
earlier of a Liquidation Event, or a transaction pursuant to Section 3.10, then
all shares of Management Stock which have vested pursuant to Dollar Vesting but
have not yet become vested due solely to Time Vesting shall become Vested Shares
at the time of such event if the Management Stockholder is still employed at the
time of such event by either the Company or any of its subsidiaries (or the
Management Stockholder's employment was terminated due to death or disability)
and all shares of Management Stock for which Dollar Vesting has not occurred
shall be forfeited and cancelled on the stock transfer records of the Company
without payment therefor to the holder.

                  (d) Upon the closing of a Qualified Public Offering, (i) all
Management Stock that is Vested Shares because both Dollar Vesting and Time
Vesting have occurred shall be retained by the Management Stockholders, (ii) all
Management Stock for which Dollar Vesting has not occurred shall automatically
and without any action on the part of the holder thereof or the Company
terminate and convert solely into the right to receive the Management
Stockholder's Original Cost for such shares from the Company, and (iii) all
Management Stock for which Dollar Vesting has occurred but for which Time
Vesting has not yet occurred shall be retained by the Management Stockholders
and shall not vest until Time Vesting has occurred. Each holder of any
Management Stock terminated pursuant to (ii) above shall return all applicable
stock certificates to the Company for termination (provided that the failure to
so deliver such shares shall in no way effect the termination thereof).

          SECTION 4.2 REPURCHASE OPTION FOR MANAGEMENT STOCK.

                  (a) Subject to the remaining provisions of this Section 4.2,
shares of Management Stock (the "Available Shares"), including both Vested
Shares and Unvested Shares (whether held by the Management Stockholder or one or
more of the Management Stockholder's Permitted Transferees), are subject to
repurchase by the other Management Stockholders (the "Non-Terminating Management
Stockholders") and the Company in the event such Management Stockholder ceases
to be employed by the Company and its subsidiaries on or before January 31, 2007
as follows:

                         (i) If the Management Stockholder ceases to be employed
     by the Company or any of its subsidiaries by reason of death or Disability,
     no shares of Management Stock, whether Vested Shares or Unvested Shares,
     owned by such Management Stockholder shall be subject to repurchase
     pursuant to this Section 4.2(a).

                         (ii) If the Management Stockholder ceases to be
     employed by the Company or any of its subsidiaries by reason of voluntary
     resignation or by reason of termination without Cause, all of such
     Management Stockholder's Unvested Shares shall be subject to repurchase,
     and the purchase price of each such share subject to repurchase pursuant to
     this Section 4.2 shall be the Management Stockholder's Original Cost for
     such share.

                                       23
<PAGE>

                         (iii) If the Management Stockholder ceases to be
     employed by the Company or any of its subsidiaries by reason of termination
     with Cause, that Management Stockholder's Unvested Shares and Vested Shares
     shall be subject to repurchase and the purchase price for each Unvested
     Share and Vested Share of Management Stock subject to repurchase pursuant
     to this Section 4.2 shall be the Management Stockholder's Original Cost for
     such share.

                  (b) On or before the 30th day (the "Available Shares Notice
Date") after the occurrence of termination of the employment of a Management
Stockholder as described in the preceding subsections of this Section 4.2, the
Company shall give the Non-Terminating Management Stockholders notice (the
"Available Shares Notice") of the termination indicating the number of Available
Shares available for repurchase pursuant to this Section 4.2, and the Company
shall deliver a copy of the Available Shares Notice to each holder of Available
Shares. The Available Shares Notice will set forth the number of Available
Shares that may be acquired from the Management Stockholder or his Permitted
Transferee, as the case may be, and the aggregate consideration to be paid for
such shares. Subject to Section 4.2(f), the Non-Terminating Management
Stockholders as a group and the Company shall each have the option for a period
of 30 days following the Available Shares Notice Date to acquire 50% of the
Available Shares in accordance with the procedure described in this Section 4.2.
On or before the expiration of such 30-day period, each of the Non-Terminating
Management Stockholders and the Company shall give written notice to each holder
of the Available Shares and each Non-Terminating Management Stockholder and the
Company of its election to acquire all or any part or the Available Shares and
the number of Available Shares which the Company or such Non-Terminating
Management Stockholders elect not to acquire (the "Remaining Available Shares").
From the date of the last such notice by the Non-Terminating Management
Stockholders and the Company until the 45th day after the Available Shares
Notice Date, the Non-Terminating Management Stockholders shall have the sole and
exclusive option to acquire the Remaining Available Shares from the Company's
50% allocation of the Available Shares and the Company shall have the sole and
exclusive option to acquire the Remaining Available Shares from the
Non-Terminating Management Stockholders as a group's 50% allocation of Available
Shares in accordance with the procedures described in this Section 4.2. The
Non-Terminating Management Stockholders may, by agreement, allocate among
themselves the right to acquire such part of the Available Shares and/or the
Remaining Available Shares that will be acquired by the Non-Terminating
Management Stockholders. In the absence of such an agreement among the
Non-Terminating Management Stockholders, each Non-Terminating Management
Stockholder will be entitled to give written notice (the "Available Shares
Election Notice") to each holder of Available Shares, to the Company and to the
Non-Terminating Management Stockholders, on or before the 45th day after the
Available Shares Notice Date, of such Non-Terminating Management Stockholder's
election to acquire all or any part of its Proportionate Percentage of the
Available Shares plus all or part of its Proportionate Percentage of the
Remaining Available Shares that are not being acquired by the Non-Terminating
Management Stockholders, including a statement of the maximum number of
Remaining Available Shares that such Non-Terminating Management Stockholder is
willing to purchase. Any Remaining Available Shares not subscribed for pursuant
to the prior sentence by the Non-Terminating Management Stockholders shall be
deemed to be re-offered to and accepted by the Non-Terminating Management

                                       24
<PAGE>

Stockholders exercising their rights to purchase Remaining Available Shares with
respect to the lesser of (A) the amount specified in their respective Available
Shares Election Notices and (B) an amount equal to their respective
Proportionate Percentages with respect to such deemed offer. Such deemed offer
and acceptance procedures described in the immediately preceding sentence shall
be deemed to be repeated until either (x) all of the Remaining Available Shares
are accepted by the Non-Terminating Management Stockholders or (y) no
Non-Terminating Management Stockholders desires to subscribe for more Remaining
Available Shares. The Company shall give written notice (a "Repurchase Notice")
to each Non-Terminating Management Stockholder and the holders of the Available
Shares within five days following the expiration of the periods described in
this Section 4.2(b) of the number or amount of Available Shares that have been
elected to be purchased by the Company and the Non-Terminating Management
Stockholders, and the Company shall set a reasonable place and time from the
date thereof for the closing of the purchase and sale of the Available Shares.
The number of Available Shares to be repurchased shall first be satisfied to the
extent possible from the Available Shares held by the Management Stockholder at
the time of delivery of the Repurchase Notice. If the number of Available Shares
then held by the Management Stockholder is less than the number of Available
Shares that the Non-Terminating Management Stockholders and the Company have
elected to purchase, the Non-Terminating Management Stockholders and the Company
shall purchase the remaining Available Shares (by class) elected to be purchased
from the Permitted Transferees of such Management Stockholder under this
Agreement pro rata, determined in each case according to the number of Available
Shares (by class) held by such Permitted Transferees at the time of delivery of
such Repurchase Notice (determined as nearly as practicable to the nearest whole
share).

                  (c) The closing of the purchase of Available Shares pursuant
to this Section 4.2 shall take place on the date designated by the Company in
the Repurchase Notice, which date shall not be more than 60 days nor less than
five days after the delivery of the Repurchase Notice. The Other Management
Stockholders and/or the Company will pay for Available Shares to be purchased
pursuant to this Section 4.2 by delivery of, in the case of the Other Management
Stockholders, a check or wire transfer of funds and, in the case of the Company,
(i) a check or wire transfer of funds, (ii) in the event the Company is
prohibited by the Company's Certificate of Incorporation, Bylaws, or applicable
statutory or contractual provisions, a subordinated promissory note or notes
payable on commercially reasonable terms if the use of such a promissory note is
not prohibited, or (iii) both (i) and (ii) in the aggregate amount of the
purchase price for such shares. Any notes issued by the Company pursuant to this
Section 4.2(c) shall be subject to any restrictive covenants (including
limitations or restrictions on the payment of interest) to which the Company is
subject at the time of such purchase. The purchasers of any Available Shares
hereunder will be entitled to require all of the signatures of each seller of
such Available Shares to be notarized and to receive representations and
warranties from each such seller regarding (A) such seller's power, authority
and legal capacity to enter into such sale and to transfer valid right, title
and interest in such Available Shares, (B) such seller's ownership of such
Available Shares and the absence of any liens, pledges, and other encumbrances
on such Available Shares, and (C) the absence of any violation, default, or
acceleration of any agreement or instrument pursuant to which such seller or the
assets of such seller are bound as the result of such sale.

                                       25
<PAGE>

                  (d) The right of the Other Management Stockholders and the
Company to repurchase Available Shares pursuant to this Section 4.2 shall
terminate upon the 125th calendar day following the date on which such Available
Shares first became subject to repurchase pursuant to this Section 4.2.

                  (e) In the event that Available Shares are repurchased
pursuant to this Section 4.2, the holders of such Available Shares will take all
steps necessary and desirable to obtain all required third-party, governmental
and regulatory consents and approvals and take all other actions necessary and
desirable to facilitate consummation of such repurchase(s) in a timely manner.

                  (f) If the Company purchases any Available Shares pursuant to
this Section 4.2, the compensation committee of the Company shall promptly meet
to discuss, and shall use its reasonable business judgment to determine, an
allocation of such shares among employees and potential employees of the
Company. If requested by any Management Stockholder, the compensation committee
shall allow such Management Stockholder to provide suggestions and comments
concerning such allocation and shall consult with such Management Stockholder
concerning the allocation.

          SECTION 4.3 BUYBACK OF CERTAIN SHARES OF STOCK.

                  (a) Upon the occurrence of an Event of Default, as described
in Section 4.2(a) of the Stock Purchase Agreement (an "Event"), the Company
shall have the right to repurchase, for a purchase price equal to 50% of the
Original Cost, up to the total number of shares of Series B Preferred and Series
B Conversion Shares owned by such Defaulting Stockholder (as such term is
defined in the Stock Purchase Agreement), or his Permitted Transferees, as the
case may be. Any Series B Conversion Shares or shares of Series B Preferred
available for repurchase under this Section 4.3(a) shall be referred to herein
as "Eligible Shares." The Company may exercise this right upon the vote of a
majority of the Board of Directors excluding the appointee of the Defaulting
Shareholder, if any.

                  (b) The Company may elect to purchase all or any portion of
the Eligible Shares by delivering written notice (the "Eligibility Notice") to
the holder or holders of Eligible Shares. The Eligibility Notice will set forth
the number of Eligible Shares to be acquired from each holder, the aggregate
consideration to be paid for such shares and the time and place for the closing
of the transaction.

                  (c) If, for any reason, the Company shall be prohibited from
purchasing or shall otherwise decline to purchase all of the Eligible Shares
pursuant to this Section 4.3, the Company may permit all Investor Stockholders
(other than the Investor Stockholder whose Series B Conversion Shares and shares
of Series B Preferred have become Eligible Shares) to purchase such unpurchased
Eligible Shares in accordance with their Proportionate Percentage (calculated
solely with respect to the Investor Stockholders). As soon as practicable after
the Company has determined that it will not purchase all of the Eligible Shares,
but in any event within 10 days after the delivery of the Eligibility Notice,
the Company shall give written notice (the "Further Eligibility Notice") to such
other Investor Stockholders

                                       26
<PAGE>

setting forth the number of remaining Eligible Shares and the aggregate purchase
price for such shares. Such other Investor Stockholders may elect to purchase
any or all of the remaining Eligible Shares by delivering written notice (the
"Eligibility Election Notice") to the Company within 30 days after receipt of
the Further Eligibility Notice from the Company. As soon as practicable, and in
any event within 15 days after receipt of the Eligibility Election Notice, the
Company shall notify the Defaulting Stockholder as to the number of Eligible
Shares being purchased from such holder by such other Investor Stockholders (the
"Supplemental Eligibility Notice").

                  (d) The closing of the purchase of Eligible Shares pursuant to
this Section 4.3 shall take place on the date designated by the Company in the
Eligibility Notice or Supplemental Eligibility Notice, which date shall not be
more than 60 days nor less than five days after the delivery of the later of the
Eligibility Notice or Supplemental Eligibility Notice. The Company and/or the
electing Investor Stockholders will pay for Eligible Shares to be purchased
pursuant to this Section 4.3 by delivery of, in the case of the Investor
Stockholders, a check or wire transfer of funds and, in the case of the Company,
(i) a check or wire transfer of funds, (ii) a subordinated note or notes bearing
interest at a rate of 7% per annum and otherwise payable on or prior to the
earlier of an Initial Public Offering or Change of Control or 10 years from the
date of issue, or (iii) both (i) and (ii) as the Company may, in its sole
discretion, determine in the aggregate amount of the purchase price for such
Eligible Shares. Any notes issued by the Company pursuant to this Section 4.3(d)
shall be subject to any restrictive covenants (including limitations or
restrictions on the payment of interest) to which to Company is subject at the
time of such purchase. The purchasers of any Eligible Shares hereunder will be
entitled to require all of the signatures of each seller of such Eligible Shares
to be notarized and to receive representations and warranties from each such
seller regarding (A) such seller's power, authority and legal capacity to enter
into such sale and to transfer valid right, title and interest in such Eligible
Shares, (B) such seller's ownership of such Eligible Shares and the absence of
any liens, pledges and other encumbrances on such Eligible Shares, and (C) the
absence of any violation, default or acceleration of any agreement or instrument
pursuant to which such seller or the assets of such seller are bound as the
result of such sale.

                  (e) The right of the Company and the Investor Stockholders to
repurchase Eligible Shares pursuant to this Section 4.3 shall terminate upon the
91st calendar day following the date on which such Eligible Shares first became
subject to repurchase pursuant to this Section 4.3.

                  (f) In the event that Eligible Shares are repurchased from an
Investor Stockholder pursuant to this Section 4.3, such Investor Stockholder
will take all steps necessary and desirable to obtain all required third-party,
governmental and regulatory consents and approvals and take all other actions
necessary and desirable to facilitate consummation of such repurchase(s) in a
timely manner.

          SECTION 4.4 FINANCIAL REPORTS.

                  (a) The Company shall furnish the following to each Investor
Stockholder who holds more than two percent (2%) of the Company's outstanding
Common

                                       27
<PAGE>

Stock (calculated based on the fully diluted Common Stock equivalent percentage
ownership, as if all shares of Series A Preferred have been converted into
shares of Common Stock at the "Conversion Ratio" for such shares (as defined in
the Certificate of Designations for the Series A Preferred) and all shares of
Series B Preferred had been converted into shares of Common Stock at the
Conversion Ratio:

                         (i) Within 45 days after the end of each fiscal month,
     a report estimating oil and gas production for such month, which report is
     used by the Company for internal control purposes, and a statement of
     income and cash flows for such fiscal month, together with a comparison of
     such statements to the annual budget of the Company for such periods;

                         (ii) Within 45 days after the end of each fiscal
     quarter, an unaudited balance sheet as of the end of such quarter and an
     unaudited related income statement, statement of stockholders equity and
     statement of cash flows for such quarter including any footnotes thereto
     (if any) prepared in accordance with generally accepted accounting
     principles, consistently applied, together with a comparison of such
     statements to the annual budget of the Company for such periods;

                         (iii) Within 90 days after the end of each fiscal year,
     an audited balance sheet as of the end of such fiscal year and the related
     income statement, statement of stockholders equity and statement of cash
     flows for such fiscal year prepared in accordance with generally accepted
     accounting principles, consistently applied and a signed audit letter from
     the Company's auditors who shall be selected from among the "Big 4"
     nationally recognized accounting firms;

                         (iv) Within 90 days after the end of each fiscal year,
     a reserve report prepared by a reservoir engineer acceptable to the Board
     of Directors;

                         (v) Within 30 days before the end of each fiscal year,
     a consolidated annual budget approved by the Board of Directors of the
     Company, together with a consolidated annual capital expenditure forecast,
     including estimated Capital Calls (as defined in the Stock Purchase
     Agreement);

                         (vi) Within 30 days after the occurrence of any
     material event, notice of such event together with a summary describing the
     nature of the event and its impact on the Company; and

                         (vii) Such other information to the Stockholders
     entitled to receive information pursuant to this Section 4.4 as such
     Stockholders or their advisors may reasonably request.

                                       28
<PAGE>

                  (b) Notwithstanding anything to the contrary contained in
Section 6.12, the obligations of the Company to furnish information pursuant to
this Section 4.4 shall cease upon the closing of a Qualified Public Offering.

                  (c) The Company shall use its best efforts to cause the Board
of Directors to hold meetings no less frequently than quarterly, and at such
meetings the Company shall report to the Board of Directors on, among other
things, its business activities, prospects, and financial position.

                  (d) The Company shall permit any Investor Stockholder or its
representatives to visit and inspect any of the properties of the Company,
including its books of account and other records (and make copies of and take
extracts from such books and records), and to discuss its affairs, finances, and
accounts with the Company's officers and its independent public accountants, all
at such reasonable times during the Company's usual business hours and as often
as any such person may reasonably request.

                                    ARTICLE V

                    SPECIAL MANAGEMENT/GOVERNANCE PROVISIONS

          SECTION 5.1 CERTIFICATE OF INCORPORATION: NO CONFLICT WITH AGREEMENT.

          Attached hereto as Exhibits B and C are copies of the Certificate of
Incorporation and Bylaws, respectively, of the Company which are in effect as of
the date hereof. Each Stockholder shall vote his shares of capital stock, and
shall take all the actions necessary, to ensure that the Certificate of
Incorporation and Bylaws of the Company do not, from time to time, conflict with
the provisions of this Agreement; provided, however, that nothing in this
Section 5.1 shall be interpreted as restricting in any respects the ability of
the Investor Stockholders to amend the Certificate of Incorporation in
accordance with the procedures established in this Agreement and the Certificate
of Incorporation for such amendment, and in the event of a conflict between any
such amendment and the provisions of this Agreement, the Certificate of
Incorporation shall control.

          SECTION 5.2 BOARD OF DIRECTORS.

                  (a) From and after the date hereof and until the consummation
of a Qualified Public Offering, subject to Section 5.8, the Company shall
exercise all authority under applicable law, and the Stockholders and their
assigns shall vote their shares of capital stock, at any regular or special
meeting of stockholders called for the purpose of filling positions on the Board
of Directors of the Company, or in any written consent executed in lieu of such
meeting of stockholders and shall take all the actions necessary, to ensure that
the Board of Directors shall consist of eight members and to ensure the election
to the Board of Directors of the Company of eight individuals: (i) two of which
shall be designated from among the officers of the Company (other than the chief
executive officer) by the Management Stockholders holding a majority of the
shares of Common Stock held by all Management Stockholders (the initial nominees
being J. Frank Keller and Fredrick J. Barrett) and one of which shall be the
chief executive officer of

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the Company (collectively, the "Management Nominees"), (ii) one of which shall
be designated by Warburg Pincus Private Equity VIII, L.P. or its assignees who
are Affiliates (the "Warburg Nominee") (the initial Warburg Nominee being
Jeffrey A. Harris), (iv) one of which shall be designated by GS Capital Partners
2000, L.P. or its assignees who are Affiliates (the "Goldman Nominee") (the
initial Goldman Nominee being Henry Cornell), (v) one of which shall be
designated by J.P. Morgan Partners (BHCA), L.P. or its assignees who are
Affiliates (the "JP Morgan Nominee", and collectively with the Warburg Nominee
and the Goldman Nominee, the "Investor Nominees") (the initial JP Morgan Nominee
being Christopher Behrens), and (vi) two of which shall be appointed upon the
affirmative vote of at least 75% of the remaining directors (the "Independent
Nominees") (one of the initial Independent Nominees being Philippe Schreiber and
the other of which shall be designated after the date hereof). The parties agree
to cause their director nominees to take all actions necessary to elect (i)
William Barrett as the Chairman of the Board of Directors during such time as
William Barrett is serving as a Director of the Company, and (ii) the chief
executive officer of the Company as the Chairman of the Board of Directors
during such time as William Barrett is not serving as a Director of the Company.

                  (b) Each Investor Nominee shall have the right to bring one
observer (each, an "Observer") and any other person approved by the chief
executive officer of the Company to each meeting of the Board of Directors and
any committee thereof. The Chief Financial Officer of the Company shall have the
right to be an additional Observer. Each Investor Nominee and each Investor
Nominee's Observer shall be full-time employees or partners of such Investor
Stockholder or any of its Affiliates.

                  (c) The Company shall have an audit committee (the "Audit
Committee"), a compensation committee (the "Compensation Committee") and such
other committees established by the Board of Directors in accordance with the
Certificate of Incorporation and the Bylaws of the Company, each such committee
to be composed or at least three (3) members, and such greater number of
Directors as shall be established by the Board of Directors. The Audit Committee
and the Compensation Committee shall each include the three Investor Nominees as
members. The three Investor Nominees shall each have the right to be appointed
to any other committees that the Board of Directors may establish.

                  (d) None of the Management Nominees or the Investor Nominees,
or the Observers appointed by the Investor Nominees, will be paid any fee for
serving on the Board of Directors. All of the Directors will be entitled to
reimbursement for reasonable out-of-pocket expenses in attending meetings of the
Board of Directors.

                  (e) The Company shall not do any of the following, or agree to
do any of the following, without the prior affirmative vote of a majority of the
Board of Directors, which majority shall include a majority of the Investor
Nominees:

                         (i) sell, merge (including pursuant to a Qualified
     Merger), consolidate or consummate any similar transaction or engage in a
     Sale of the Company; provided however, that after March 28, 2009, any such
     transaction may be approved by a simple majority of the Board of Directors
     if such transaction results in the holders of the Series B Preferred
     receiving an amount

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     equal to the greater of the Accreted Value per share (as defined in the
     Certificate of Incorporation) or the amount that would be received by such
     holders of Series B Preferred upon liquidation in accordance with the terms
     of such Series B Preferred.

                         (ii) repurchase or issue any capital stock or
     equity-linked securities of the Company or any subsidiary of the Company
     other than (A) pursuant to the Company's 2002 Stock Option Plan as in
     effect on the date hereof (and as amended in the manner contemplated by
     Section 5.2(e)(xii)) and the Company's 2003 Stock Option Plan as in effect
     on the date hereof, (B) pursuant to the Purchase Plan, (C) pursuant to the
     Tyree Option, (D) pursuant to the Barron Option, and/or (E) Series B
     Preferred pursuant to the Stock Purchase Agreement;

                         (iii) declare or pay any dividends or distributions on
     the Company's capital stock other than pursuant to paragraphs 4 or 5 of the
     Series B Certificate of Designations;

                         (iv) approve the Company's annual budget;

                         (v) make expenditures during the fiscal year covered by
     the Company's annual budget approved in accordance with (iv) above, other
     than for acquisitions of oil and gas producing and nonproducing properties
     and leasehold interests, of amounts that in the aggregate exceed the
     aggregate amounts approved for all expenditures in the annual budget by 5%
     of such approved amounts, or $5,000,000, whichever is greater;

                         (vi) make any acquisitions during any fiscal year that,
     in the aggregate, exceed $25,000,000;

                         (vii) incur (A) any single indebtedness in excess of
     $25,000,000, or (B) after March 28, 2003, aggregate indebtedness in excess
     of an amount equal to two times the Company's earnings before interest,
     taxes, depletion, depreciation and amortization (EBITDA) for the prior four
     fiscal quarters, on a pro forma basis with respect to any acquisitions;

                         (viii) divest itself of assets for an aggregate amount
     of $80,000,000 or more, or assets representing 25% or more of the Company's
     total assets;

                         (ix) issue any capital stock of the Company that is on
     parity with, or senior to, the Series B Preferred;

                         (x) amend (by merger or otherwise) the Company's
     Certificate of Incorporation (including all certificates of designation
     with respect thereto) or Bylaws;

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<PAGE>

                         (xi) enter into any material transaction with any
     officers, directors, employees or Affiliates of the Company, including
     issuances of management stock options other than those issued pursuant to
     the Company's 2002 Stock Option Plan; or

                         (xii) (1) during the Takedown Period (as defined in the
     Stock Purchase Agreement), in the aggregate issue options pursuant to the
     Company's 2002 Stock Option Plan (A) to purchase an aggregate number of
     shares that exceeds the lesser of 5,500,000 shares or 8.340066% of the then
     outstanding Common Stock on a fully diluted basis excluding Management
     Stock that has not vested as a result of Dollar Vesting (calculated on the
     basis that all shares of Series B Preferred have been converted at the
     Conversion Ratio and all shares of Series A Preferred have been converted
     at the "Conversion Ratio" as defined in the Certificate of Designations for
     the Series A Preferred Stock), with an exercise price of less than $6.50
     per share, (B) to purchase an aggregate number of shares that exceeds the
     lesser of 2,150,000 shares or 3.30769% of the then outstanding Common Stock
     on a fully diluted basis excluding Management Stock that has not vested as
     a result of Dollar Vesting (calculated on the basis that all shares of
     Series B Preferred have been converted at the Conversion Ratio and all
     shares of Series A Preferred have been converted at the "Conversion Ratio"
     as defined in the Certificate of Designations for the Series A Preferred
     Stock), with an exercise price of less than $0.04412 per share, (C) with a
     vesting schedule more favorable than the Time Vesting for Management Stock
     contained in Section 4.1 of this Agreement, or (D) with a term of more than
     10 years, or (2) at any time, issue any options pursuant to any form of
     stock option agreement that has not been approved by a majority of the
     Investor Nominees (which form of agreement shall include a provision
     providing for the cancellation of such stock options in the manner
     contemplated by Section 3.10 and a provision providing that the value upon
     cancellation or otherwise shall be based on paragraph 4 of the Certificate
     of Designations for the Series B Preferred Stock) or pursuant to the
     Company's 2002 Stock Option Plan until such plan has been amended or
     amended and restated in a form approved by a majority of the Investor
     Nominees.

          SECTION 5.3 REMOVAL.

                  (a) If during the term of a director designated by the
Management Stockholders pursuant to Section 5.2, holders of a majority of the
capital stock held by the Management Stockholders request that such director be
removed (with or without Cause) by written notice to the Investor Stockholders,
then such director may be removed, with or without Cause, upon the affirmative
vote of holders of a majority of the outstanding shares of capital stock, and
each Stockholder hereby agrees to vote all shares of capital stock owned or held
of record to effect such removal or consent in writing to effect such removal
upon such request. An Investor Nominee may be removed during his or her term of
office, with or without cause, only by the Person entitled to designate such
Investor Nominee pursuant to Section 5.2(a) or Section 5.8. If an Investor
Stockholder becomes a Defaulting Stockholder or Non-Participating Stockholder at
such time as the Investor Stockholder has a representative serving on the Board
of

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Directors as an Investor Nominee, each Stockholder hereby agrees to vote all
shares of capital stock owned or held of record to effect the removal of such
Investor Nominee or consent in writing to effect such removal upon such request
if such Investor Nominee fails to resign.

                  (b) No director shall be removed without Cause except as
provided in Section 5.3(a) hereof, provided, however, any director shall be
removed for Cause if the holders of a majority of the outstanding shares of
capital stock consent in writing to such removal, and provided further that any
Management Nominee may be removed without Cause if the holders of 60% or more of
the outstanding shares of Series B Preferred consent in writing to such removal.
Each Management Stockholder that is a member of the Board of Directors agrees to
resign as a member of the Board of Directors upon the termination of his
employment (for any reason) with the Company.

          SECTION 5.4 VACANCIES.

          In the event that a vacancy is created on the Board of Directors by
the death, disability, retirement, resignation or removal (with or without
Cause) of a director, each Stockholder will vote for, and cause the directors
designated by it to vote for, the individual designated to fill such vacancy by
whichever of the Stockholders designated (pursuant to Section 5.2 hereof) the
director whose death, disability, retirement, resignation or removal (with or
without Cause) resulted in such vacancy on the Board (in the manner set forth in
Section 5.2) and the Company shall exercise all authority under applicable law
to give effect to this Section 5.4; provided, however, that such other
individual so designated may not previously have been a director of the Company
who is removed for Cause from the Board of Directors, and provided further,
however, that any Non-Participating Stockholder and Defaulting Stockholder shall
lose its right, if any, to designate a director. In the event that a vacancy is
created on the Board of Directors as a result of the removal of a director
designated by a Stockholder who has become a Non-Participating Stockholder or a
Defaulting Stockholder, such vacancy shall be filled as provided in Section 5.8
hereof.

          SECTION 5.5 COVENANT TO VOTE.

          Each Stockholder hereby agrees to take all actions necessary to call,
or cause the Company and the appropriate officers and directors of the Company
to call, a special or annual meeting of the stockholders of the Company and to
vote all shares of the capital stock owned or held of record by such Stockholder
at any such annual or special meeting in favor of, or take all actions by
written consent in lieu of any such meeting necessary to cause, the election as
members of the Board of Directors of those individuals so designated in
accordance with, and otherwise to effect the intent of Article V. In addition,
each Stockholder agrees to vote the shares of capital stock owned by such
Stockholder upon any other matter arising under this Agreement submitted to a
vote of the Stockholders in a manner that will implement the terms of this
Agreement.

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          SECTION 5.6 DESIGNATION OF PROXY.

          In order to effectuate the provisions of this Article V and in
addition to and not in lieu of Sections 5.2 through 5.5 hereof, each of the
Management Stockholders hereby grants to William J. Barrett a proxy to vote at
any meeting of Stockholders or take any action by written consent in lieu of
such meeting with respect to, all of the shares of Common Stock owned or held of
record by such Management Stockholders solely for (i) the election of directors
designated in accordance with Section 5.2 hereof, and (ii) the election of a
director to fill any vacancy on the Board of Directors in accordance with
Section 5.4 hereof. Such proxy to vote is coupled with an interest and is
therefore irrevocable.

          SECTION 5.7 INVESTOR STOCKHOLDER RIGHTS.

                  (a) At any time when shares of Series B Preferred Stock are
outstanding, and in addition to any other vote required by law, the Certificate
of Incorporation or certificates of designation with respect thereto, the
Corporation shall, upon notice of the approval of the holders of at least sixty
percent (60%) of the then outstanding shares of Series B Preferred Stock given
in writing or by vote at a meeting, consenting or voting (as the case may be)
separately as a series, undertake to cause (i) the removal of any or all of the
Management Nominees and/or the termination of any employees, (ii) the
termination of the Takedown Period with respect to Capital Calls, as such terms
are defined in the Stock Purchase Agreement, (iii) an Initial Public Offering,
or (iv) a Qualified Merger.

                  (b) At any time when shares of Series B Preferred Stock are
outstanding, and in addition to any other vote required by law, the Certificate
of Incorporation or certificates of designation with respect thereto, the
Corporation shall, upon the written election of the holders of at least seventy
percent (70%) of the then outstanding shares of Series B Preferred Stock or by
vote at a meeting, consenting or voting (as the case may be) separately as a
series, use all commercially reasonable efforts to negotiate and enter into a
business transaction or series of related transactions involving the sale of the
assets or capital stock of the Company that would result in a Change of Control.

                  (c) Each Stockholder hereby covenants and agrees that it shall
vote its shares of Common Stock, Series A Preferred and Series B Preferred to
enforce compliance with Section 5.7(a) and (b), including without limitation,
voting to remove any director who fails to comply with a request properly made
under Section 5.7(a) and (b). Any Change of Control or Qualified Merger shall be
subject to the satisfaction of the conditions set forth in Section 3.10(c) as if
such transaction were an Approved Sale.

                  (d) Each Investor Stockholder hereby covenants and agrees that
it shall give the chief executive officer of the Company at least five (5)
business days written notice prior to the taking of any action by written
consent, including without limitation, any action permitted under Section 5.7(a)
hereof, and furthermore shall give the chief executive officer the opportunity
to meet with the Investor Stockholders to discuss any such action proposed to be
taken by written consent prior to the execution thereof.

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          SECTION 5.8 VOTING RIGHTS.

                  (a) From and after the date that an Investor Stockholder
becomes a Non-Participating Stockholder or a Defaulting Stockholder, such
Investor Stockholder shall forfeit the right to (i) vote on any matters as are
expressly required or permitted in the Certificate of Incorporation, the Bylaws,
this Agreement or the Stock Purchase Agreement to be voted on by the Series B
Preferred as a separate class, except to the extent prohibited by law or
expressly provided herein or therein, and all such shares held by such
Non-Participating or Defaulting Stockholder shall be deemed to be not
outstanding for all such purposes, and (ii) appoint a nominee to the Board of
Directors pursuant to Section 5.2 hereof. Such Non-Participating Stockholder or
Defaulting Stockholder shall cause its Investor Nominee, if any, to resign if
requested by the Company. In the event an empty Board of Directors seat is
created pursuant to this Section 5.8, such seat shall be filled by the nominee
of the Investor Stockholder who holds the largest number of shares of Series B
Preferred and that does not have a nominee on the Board of Directors and is not
itself a Non-Participating Stockholder or a Defaulting Stockholder or, if such
next largest Investor Stockholder does not desire to or cannot appoint a
nominee, by the Investor Stockholder who holds the next largest number of shares
of Series B Preferred and who does not otherwise have a nominee on the Board of
Directors and is not itself a Defaulting Stockholder or, if no such Investor
Stockholder exists or is willing or able to appoint such a nominee, by the
Investor Stockholder holding the largest number of shares of Series B Preferred
Stock who is not a Defaulting Stockholder or Non-Participating Investor.

                  (b) From and after the date that an Investor Stockholder
becomes a Non-Participating Stockholder or a Defaulting Stockholder, such
Investor Stockholder hereby agrees to grant to the chief executive officer of
the Company a proxy (such proxy to be coupled with an interest and therefore
irrevocable) to vote such shares of Common Stock and Series B Preferred owned by
such Non-Participating Stockholder or Defaulting Stockholder, as the case may
be; provided, however, that such proxy will not be in effect for any votes that
(i) are required by law to be voted by such Non-Participating Stockholder or
Defaulting Stockholder, as the case may be, (ii) are expressly required or
permitted in the Certificate of Incorporation, the Bylaws, the Stock Purchase
Agreement or this Agreement to be voted by such Non-Participating Stockholder or
Defaulting Stockholder, as the case may be, and (iii) for any vote pertaining to
any amendment, modification, or waiver that would adversely affect the rights of
such Non-Participating Stockholder or Defaulting Stockholder, as the case may
be, in its capacity as a Stockholder, without similarly affecting the rights of
all Stockholders of the same class or series, in their capacity as Stockholders
of such class or series. The chief executive officer will, pursuant to such
proxy, vote such shares of Common Stock and Series B Preferred owned by such
Non-Participating Stockholder or Defaulting Stockholder, as the case may be, in
the same manner (i.e., in favor, abstain or against) and in the same proportion
as all votes cast by the other Stockholders.

          SECTION 5.9 VCOC RIGHTS.

          Certain rights set forth in this Article V are, in part, intended to
satisfy the requirement of contractual management rights for purposes of
qualifying the ownership interests of each of certain Investor Stockholders in
the Company as venture capital investments for

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<PAGE>

purposes of the Department of Labor's "plan assets" regulations ("Contractual
Management Rights"), and in the event such rights are not satisfactory for such
purpose or are lost by reason of the operation of this Agreement, the Company
and each of such Investor Stockholders shall reasonably cooperate in good faith
to agree upon mutually satisfactory Contractual Management Rights which satisfy
such regulations.

          SECTION 5.10 BUSINESS OPPORTUNITIES.

          As soon as practicable after the date hereof, the Company shall amend
its Certificate of Incorporation to include the provisions attached as Exhibit E
and shall keep such provisions in the Certificate of Incorporation of the
Company and any successor Person at all times while any Investor Stockholder
holds shares of capital stock of the Company. Each Stockholder hereby agrees to
take all actions necessary or desirable to effect the foregoing sentence,
including voting for or consenting to amendments to the Certificate of
Incorporation.

                                   ARTICLE VI

                                  MISCELLANEOUS

          SECTION 6.1 MANNER OF GIVING NOTICE.

          All notices required to be given hereunder shall be in writing and
shall be deemed to be duly given if personally delivered, telecopied and
confirmed, or mailed by certified mail, return receipt requested, or overnight
delivery service with proof of receipt maintained, at the following address (or
any other address that any such party may designate by written notice to the
other parties):

          Bill Barrett Corporation
          1099 18th Street, Suite 2300
          Denver, Colorado 80202
          Facsimile:  (303) 291-0420

          If to any Stockholder, at his address as set forth on Exhibit A of
this Agreement.

          Any such notice shall, if delivered personally, be deemed received
upon delivery; shall, if delivered by telecopy, be deemed received on the first
business day following confirmation; shall, if delivered by overnight delivery
service, be deemed received the first business day after being sent; and shall,
if delivered by mail, be deemed received upon the earlier of actual receipt
thereof or five business days after the date of deposit in the United States
mail.

          SECTION 6.2 WAIVER OF NOTICE.

          Whenever any notice is required to be given to any Stockholder of the
Company under the provisions of this Agreement, a waiver thereof in writing
signed by the person or persons entitled to such notice, whether before or after
the time stated therein, shall be deemed equivalent to the giving of such
notice. Attendance of a Stockholder at a meeting of the Stockholders shall
constitute a waiver of notice of such meeting, except where a Stockholder

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attends a meeting for the express purpose of objecting to the transaction of any
business on the ground that the meeting is not lawfully called or convened.

          SECTION 6.3 COUNTERPART SIGNATURES.

          This Agreement may be executed in any number of counterparts, all of
which together shall constitute a single instrument. It shall not be necessary
that any counterpart be signed by each of the Stockholders so long as each
counterpart shall be signed by one or more of the Stockholders and so long as
the other Stockholders shall sign at least one counterpart which shall be
delivered to the Company.

          SECTION 6.4 SEVERABILITY.

          If any provision of this Agreement is held to be illegal, invalid or
unenforceable under present or future laws effective during the term of this
Agreement, such provision shall be fully severable; this Agreement shall be
construed and enforced as if such illegal, invalid, or unenforceable provision
had never comprised a part of this Agreement; and the remaining provisions of
this Agreement shall remain in full force and effect and shall not be affected
by the illegal, invalid or unenforceable provision or by its severance from this
Agreement. Furthermore, in lieu of each such illegal, invalid or unenforceable
provision, there shall be added automatically as a part of this Agreement a
provision as similar in terms to such illegal, invalid or unenforceable
provision as may be possible and be legal, valid and enforceable.

          SECTION 6.5 JOINDER OF SPOUSES.

          The spouses of all married Stockholders have joined in the execution
of this Agreement in order to evidence their agreement and consent to be bound
by the terms and conditions hereof as to their interest, whether as community
property or otherwise, if any, in the shares of capital stock owned by their
respective spouses.

          SECTION 6.6 ENTIRE AGREEMENT; AMENDMENTS; AGREEMENT CONTROLS.

                  (a) This Agreement, together with the Regulatory Sideletter,
supersedes all prior agreements among the parties with respect to the subject
matter hereof. The provisions of this Agreement may only be amended, modified,
waived or terminated with the prior written consent of the holders of at least
60% of the outstanding Series B Preferred and the holders of shares representing
a majority of the outstanding Common Stock held by the Stockholders (calculated
on the basis that all shares of Series A Preferred and Series B Preferred have
been converted); provided, however, that (A) any such amendment, modification,
or waiver (but not any termination) that would adversely affect the rights
hereunder of any Stockholder, in its capacity as a Stockholder, without
similarly affecting the rights hereunder of all Stockholders of the same class,
in their capacities as Stockholders of such class, that would affect a
Stockholder's right to place an individual on the Board of Directors pursuant to
Section 5.2 or exercise its preemptive rights pursuant to Section 2.2 or that
would impose any material obligation on any Stockholder, shall not be effective
as to such Stockholder without its prior written consent, (B) Exhibit A to this
Agreement shall be deemed to be automatically amended

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<PAGE>

from time to time to reflect issuances and transfers of shares of Common Stock,
Series A Preferred and Series B Preferred made in compliance with this Agreement
and the Stock Purchase Agreement without requiring the consent of any party, and
the Company will, from time to time, distribute to the Stockholders a revised
Exhibit A to reflect any such changes, and (C) any amendment, modification or
waiver of Section 6.14 or the Regulatory Sideletter shall be subject to the
approval of JPMP.

                  (b) No waiver of any provision hereof by any party shall be
deemed a waiver by any other party nor shall any such waiver by any party be
deemed a continuing waiver of any matter by such party.

                  (c) No amendment, modification, supplement, discharge or
waiver hereof or hereunder shall require the consent of any person not a party
to this Agreement.

          SECTION 6.7 GOVERNING LAW AND VENUE.

          This Agreement shall be governed and construed in accordance with the
laws of the State of New York, without regard to the conflicts of law principles
of such state.

          SECTION 6.8 CONSENT TO JURISDICTION.

                  (a) The parties hereto hereby irrevocably submit to the
exclusive jurisdiction of the courts of the State of New York and the federal
courts of the United States of America located in New York, and appropriate
appellate courts therefrom, over any dispute arising out of or relating to this
Agreement or any of the transactions contemplated hereby, and each party hereby
irrevocably agrees that all claims in respect of such dispute or proceeding may
be heard and determined in such courts. The parties hereby irrevocably waive, to
the fullest extent permitted by applicable law, any objection which they may now
or hereafter have to the laying of venue of any dispute arising out of or
relating to this Agreement or any of the transactions contemplated hereby
brought in such court or any defense of inconvenient forum for the maintenance
of such dispute. Each of the parties hereto agrees that a judgment in any such
dispute may be enforced in other jurisdictions by suit on the judgment or in any
other manner provided bylaw. This consent to jurisdiction is being given solely
for purposes of this Agreement and is not intended to, and shall not, confer
consent to jurisdiction with respect to any other dispute in which a party to
this Agreement may become involved.

                  (b) Each of the parties hereto hereby consents to process
being served by any party to this Agreement in any suit, action, or proceeding
of the nature specified in subsection (a) above by the mailing of a copy thereof
in the manner specified by the provisions of Section 6.1.

                  (c) EACH OF THE PARTIES HERETO HEREBY IRREVOCABLY WAIVES ALL
RIGHT TO TRIAL BY JURY IN ANY ACTION, PROCEEDING OR COUNTERCLAIM ARISING OUT OF
OR RELATING TO THIS AGREEMENT.

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          SECTION 6.9 BINDING EFFECT; ASSIGNMENT.

          This Agreement shall be binding upon and shall inure to the benefit of
the Company and each Stockholder and his respective heirs, permitted successors,
permitted assigns, permitted distributees and legal representatives, and by
their signatures hereto, the Company and each Stockholder intends to and does
hereby become bound. Nothing expressed or mentioned in this Agreement is
intended or shall be construed to give any person other than the parties hereto
and their respective permitted successors and assigns any legal or equitable
right, remedy or claim under, in or in respect of this Agreement or any
provision herein contained. Notwithstanding anything herein to the contrary, the
rights under this Agreement may be assigned by a Stockholder to a transferee of
all or a portion of such Stockholder's shares provided such shares are
transferred in accordance with the terms of this Agreement; provided, that the
right to designate an Investor Nominee may not be transferred or assigned except
to an Affiliate of such Investor.

          SECTION 6.10 FUTURE ACTIONS.

          The Company and the Stockholders shall execute and deliver all such
future instruments and take such other and further action as may be reasonably
necessary or appropriate to carry out the provisions of this Agreement and the
intention of the parties as expressed herein, including if necessary any action
required to authorize and direct the officers and directors of the Company to
amend the Company's Certificate of Incorporation so that this Agreement is
enforceable under the laws of the state in which the Company is incorporated.

          SECTION 6.11 HEADINGS; EXHIBITS.

          All Article and Section headings herein are for convenience of
reference only and are not part of this Agreement, and no construction or
inference shall be derived therefrom. The Exhibits attached hereto and referred
to herein are a part of this Agreement as if fully set forth herein. All
references to Sections and Exhibits shall be deemed references to such parts of
this Agreement, unless the context shall otherwise require.

          SECTION 6.12 TERMINATION OF THIS AGREEMENT.

          Except as provided herein, this Agreement shall immediately and
automatically terminate, without any further action by any party, upon any of
the following: (i) pursuant to Section 6.6, or (ii) the dissolution, bankruptcy,
receivership or insolvency of the Company, or (iii) upon the closing of a
Qualified Public Offering or a Qualified Merger (provided that Sections 3.1(b),
4.1, 4.2 and 4.3 shall survive a Qualified Public Offering or a Qualified
Merger).

          SECTION 6.13 ADJUSTMENTS FOR STOCK SPLITS, ETC.

          Wherever in this Agreement there is a reference to a specific number
of shares of stock of the Company of any class or series, or a price per share
of such stock, or consideration received in respect of such stock, then, upon
the occurrence of any subdivision, combination, or stock dividend of such class
or series of stock, the specific number of shares or the price so referenced in
this Agreement shall automatically be proportionally adjusted to reflect the
effect

                                       39
<PAGE>

on the outstanding shares of such class or series of stock by such subdivision,
combination, or stock dividend.

          SECTION 6.14 REGULATORY MATTERS.

                  (a) Cooperation Of Other Stockholders. Each Stockholder agrees
to cooperate with the Company in all reasonable respects in complying with the
terms and provisions of the letter agreement between the Company and Investor
(as defined in the Regulatory Sideletter), a copy of which is attached hereto as
Exhibit D, regarding regulatory matters (the "Regulatory Sideletter"), including
without limitation, voting to approve amending the Company's certificate of
incorporation, the Company's by-laws or this Agreement in a manner reasonably
acceptable to the Stockholders and Investor or any Affiliate (as defined in the
Regulatory Sideletter) of Investor entitled to make such request pursuant to the
Regulatory Sideletter in order to remedy a Regulatory Problem (as defined in the
Regulatory Sideletter). Anything contained in this Section 6.14 to the contrary
notwithstanding, no Stockholder shall be required under this Section 6.14 to
take any action that would adversely affect in any material respect such
Stockholder's rights under this Agreement or as a stockholder of the Company.

                  (b) Covenant Not To Amend. The Company and each Stockholder
agree not to amend or waive the voting or other provisions of the Company's
certificate of incorporation, the Company's by-laws or this Agreement if such
amendment or waiver would cause Investor or any of its Affiliates to have a
Regulatory Problem (as defined in the Regulatory Sideletter). Investor agrees to
notify the Company as to whether or not it would have a Regulatory Problem
promptly after Investor has notice of such amendment or waiver.

                                       40
<PAGE>

     IN WITNESS WHEREOF, the parties hereto have executed and delivered this
Agreement as of the day, month and year first above written.

                                COMPANY:

                                      BILL BARRETT CORPORATION

                                      By:    /s/ J. Frank Keller
                                             -----------------------------------
                                      Name:  J. Frank Keller
                                      Title: Chief Operating Officer

<PAGE>

                           INVESTOR STOCKHOLDERS:

                              INVESTOR STOCKHOLDER:

                              COLORADO PUBLIC EMPLOYEE
                              RETIREMENT ASSOCIATION

                              By:      /s/ Norman Benedict
                                       -----------------------------------------
                                       Norman Benedict
                                       Deputy Executive Director of Investments

                              INVESTOR STOCKHOLDER:

                              GS CAPITAL PARTNERS 2000, L.P.

                              BY:      GS Advisors 2000, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              INVESTOR STOCKHOLDER:

                              GSCP 2000 OFFSHORE BBOG HOLDING, L.P.

                              BY:      GS Capital Partners 2000 Offshore, L.P.,
                                       its General Partner

                              BY:      GS Advisors 2000, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

<PAGE>

                              INVESTOR STOCKHOLDER:

                              GSCP 2000 GMBH BBOG HOLDING, L.P.

                              BY:      GSCP 2000 GmbH BBOG Holding I,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              INVESTOR STOCKHOLDER:

                              GS CAPITAL PARTNERS 2000 EMPLOYEE FUND, L.P.

                              BY:      GS Employee Funds 2000 GP, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              INVESTOR STOCKHOLDER:

                              STONE STREET FUND 2000, L.P.

                              BY:      Stone Street 2000, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              INVESTOR STOCKHOLDER:

                              STONE STREET BBOG HOLDING

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman

<PAGE>

                              Title:   Vice President

                              INVESTOR STOCKHOLDER:

                              GOLDMAN SACHS DIRECT INVESTMENT FUND 2000, L.P.

                              BY:      GS Employee Funds 2000 GP, L.L.C.,
                                       its General Partner

                              By:      /s/ John E. Bowman
                                       -----------------------------------------
                              Name:    John E. Bowman
                              Title:   Vice President

                              INVESTOR STOCKHOLDER:

                              J.P. MORGAN PARTNERS (BHCA), L.P.

                              BY:      JPMP MASTER FUND MANAGER, L.P.,
                                       ITS GENERAL PARTNER

                              BY:      JPMP CAPITAL CORP.,
                                       ITS GENERAL PARTNER

                              By:      /s/ Christopher Behrens
                                       -----------------------------------------
                                       Christopher Behrens
                                       Managing Director

                              INVESTOR STOCKHOLDER:

                              PALANTIR PARTNERS LP

                              BY:      PALANTIR ASSOCIATES LLC
                                       its General Partner

                              By:      /s/ Glenn Doshay
                                       -----------------------------------------
                                       Glenn Doshay
                                       President

<PAGE>

                              INVESTOR STOCKHOLDER:

                              THE DOSHAY FAMILY TRUST OF 1999

                              By:      /s/ Glenn Doshay
                                       -----------------------------------------
                                       Glenn Doshay
                                       Trustee

                              INVESTOR STOCKHOLDER:

                              STATE FARM MUTUAL AUTOMOBILE INSURANCE COMPANY

                              By:      /s/ John Conklin
                                       -----------------------------------------
                                       John Conklin
                                       Vice President - Common Stocks

                              By:      /s/ John Elterich
                                       -----------------------------------------
                                       John Elterich
                                       Assistant Secretary

                              INVESTOR STOCKHOLDER:

                              WARBURG PINCUS PRIVATE EQUITY VIII, L.P.

                              BY:      WARBURG PINCUS & CO.,
                                       AS GENERAL PARTNER

                              By:      /s/ Jeffrey A. Harris
                                       -----------------------------------------
                                       Jeffrey A. Harris, Partner

<PAGE>

MANAGEMENT STOCKHOLDERS:

/s/ William J. Barrett                        /s/ John F. Keller
-------------------------------               ----------------------------------
William J. Barrett                            John F. Keller

/s/ Fredrick J. Barrett                       /s/ Terry R. Barrett
-----------------------------------           ----------------------------------
Fredrick J. Barrett                           Terry R. Barrett

Robert W. Howard Trust                        The Reinecke-Alcott Trust 6/7/00
 dated August 2, 2001

     By: /s/ Robert W. Howard                     By: /s/ Kurt Reinecke
         --------------------------                   --------------------------
        Signature                                     Signature

     /s/ Robert W. Howard, Trustee                /s/ Kurt Reinecke, Trustee
     ------------------------------               ------------------------------
     Printed Name and Title                       Printed Name and Title

/s/ Lynn M. Connelly                          /s/ Patty Adair
-----------------------------------           ----------------------------------
Lynn M. Connelly                              Patty Adair

/s/ Katherine E. Lee                          /s/ Kimberly S. Vickery
-----------------------------------           ----------------------------------
Katherine E. Lee                              Kimberly S. Vickery

Huntington T. Walker and Carol N. Walker,
 tenants-in-common

     /s/ Huntington T. Walker                 /s/ Wilfred R. Roux
     ------------------------------           ----------------------------------
     Huntington T. Walker                     Wilfred R. Roux

     /s/ Carol N. Walker                      /s/ James M. Felton
     ------------------------------           ----------------------------------
     Carol N. Walker                          James Michael Felton

/s/ Dominic J. Bazile                         /s/ Peter Keller
-----------------------------------           ----------------------------------
Dominic J. Bazile II                          Peter Keller

/s/ Thomas B. Tyree, Jr.                      /s/ Lindsay Keller
-----------------------------------           ----------------------------------
Thomas B. Tyree, Jr.                          Lindsay Keller

/s/ Francis B. Barron
-----------------------------------
Francis B. Barron

[Additional stockholder signatures on file]

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