8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C.  20549

FORM 8-K

CURRENT REPORT

Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

Date of Report (date of earliest event reported):  September 10, 2010

CARRIZO OIL & GAS, INC.

(Exact name of registrant as specified in its charter)

Texas	000-29187-87	76-0415919
(State or other jurisdiction of	(Commission	(I.R.S. Employer
incorporation)	File Number)	Identification No.)

1000 Louisiana Street Suite 1500 Houston, Texas	77002
(Address of principal executive offices)	(Zip code)

Registrant’s telephone number, including area code: (713) 328-1000

Not applicable

(Former name or former address, if changed since last report.)

Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions:

[ ] Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425)

[ ] Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12)

[ ] Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b))

[ ] Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c))

Item 1.01                      Entry into a Material Definitive Agreement.

Thirteenth Amendment to Credit Agreement

Carrizo Oil & Gas, Inc. (the “Company”) entered into the Thirteenth Amendment (the “Thirteenth Amendment”) to the Credit Agreement dated as of May 25, 2006 among the Company, certain subsidiaries of the Company, the lenders party thereto and Wells Fargo Bank, N.A., as administrative agent (the “Credit Agreement”).

Pursuant to the Thirteenth Amendment, the Credit Agreement was amended to permit the transactions described below in Items 1.01 and 8.01 of this Current Report.  The Thirteenth Amendment was executed on August 23, 2010 and became effective on September 10, 2010, the date of the closing of such transactions.

The foregoing description of the Thirteenth Amendment is not complete and is qualified by reference to the complete document, which is filed as an exhibit to this Current Report and incorporated by reference herein.

Amendments to Avista Joint Venture

In connection with the execution of the agreements to enter into the transactions described below in Item 8.01 of this Current Report, on August 4, 2010, the Company and its existing joint venture partner, an affiliate of Avista Capital Partners, LP (Avista Capital Partners, LP, together with its affiliates, “Avista”) entered into Amendment No. 1 (“Amendment No. 1”) to that certain Participation Agreement (the “Participation Agreement”), dated November 3, 2008 and effective August 1, 2008, among the Company, the Company’s joint venture subsidiary, Avista Capital Partners II, L.P. and ACP II Marcellus, LLC (“ACP II”).  Amendment No. 1 provides that the proceeds from the sales of the Company’s and Avista’s properties to Reliance Marcellus II, LLC (“Relianc e”), a wholly-owned subsidiary of Reliance Holding USA, Inc. and an affiliate of Reliance Industries Limited, would be allocated separately and not subject to the joint venture allocation provisions of the original Participation Agreement.  Amendment No. 1 also provides that profits interest distributions to the Company with respect to Avista’s sale of properties to Reliance would be principally based upon the return on investment and internal rates of return associated with such properties.

In connection with the closing of the transactions described below in Item 8.01 of this Current Report, on September 10, 2010, the Company entered into an Omnibus Amendment (the “Omnibus Amendment”) that amends the Participation Agreement and other joint venture agreements with Avista.  The Omnibus Amendment provides that the properties that the Company and Avista have sold to Reliance, as well as the properties the Company commits to the new joint venture with Reliance, are not subject to the terms of the Avista joint venture, and that the Avista joint venture’s area of mutual interest will generally not include Pennsylvania, in which those properties are located.

The foregoing descriptions of Amendment No. 1 and the Omnibus Amendment are not complete and are qualified by reference to the complete documents, which are filed as exhibits to this Current Report and incorporated by reference herein.

Item 8.01                      Other Events.

On September 10, 2010, the Company completed the sale of 20% of its interests in oil and gas properties in parts of Pennsylvania in the Marcellus Shale to Reliance.  Under the purchase and sale agreement for this transaction, the Company received at the closing of the transaction $11.4 million in cash, with up to $1.7 million more expected in 2010.  As part of the consideration for the purchase, Reliance has committed to pay 75% of certain of the Company’s future development costs up to approximately $52 million, as further described below.  Simultaneous with the closing of this transaction, ACP II, which is the Company’s already existing joint venture partner in the Marcellus Shale, closed the sale of its entire interest in the same properties to Reliance for approximately $327 million.   Because of the Company’s interest in ACP II, the Company expects to receive up to approximately $44 million in cash distributions based on Avista’s sale to Reliance. The amounts to be received by Avista and the Company are subject to adjustment, pending completion of land and title matters. At the same time, the Company and Reliance also entered into agreements to form a new joint venture with respect to the interests being purchased by Reliance from the Company and Avista.  The new Carrizo/Reliance joint venture agreement covers approximately 104,400 gross acres in northern and central Pennsylvania.  Under the terms of the agreement, the Company generally retained a 40% working interest in the acreage and Reliance generally acquired a 60% working interest.  In addition to funding its own share of future development obligations, Reliance agreed to fund 75% of the Company’s portion of these costs until September 2012 or until the earlier full utilization o f the up to $52 million development carry, subject to certain conditions and extensions.  The Company will continue as operator with Reliance having the right to assume operations in certain parts of central Pennsylvania beginning in September 2011.  The Company’s Marcellus joint venture with Avista will continue and now covers approximately 140,000 gross acres, primarily in West Virginia and New York.

_________________

Statements in this Current Report and the exhibits thereto that are not historical facts, including those related to the new and existing joint ventures and sales transaction (including their benefits, results, effects and timing), the receipt and amount of additional post-closing consideration from Reliance, the receipt and amount of distributions from ACP II, the development carry, capital expenditures, Reliance’s funding and access to capital are forward-looking statements that are based on current expectations. Although the Company believes that its expectations are based on reasonable assumptions, it can give no assurance that these expectations will prove correct. Important factors that could cause actual results to differ materially from those in the forward-looking statements include purchase price and drilling carry adj ustments, lease consents and similar matters, the existence of title defects, amounts ultimately received by and from Avista, actions by joint venture partners, delays, costs and difficulties relating to the purchase and joint venture transactions, results of exploration activities, commodity price changes, capital needs and uses, market and other conditions and other risks described in the Company’s Annual Report on Form 10-K for the year ended December 31, 2009, its Quarterly Reports on Form 10-Q for the quarters ended March 30, 2010 and June 30, 2010 and its other filings with the Securities and Exchange Commission.

Item 9.01.                      Financial Statements and Exhibits.

(d)           Exhibits.

Exhibit Number	Description
10.1	Thirteenth Amendment to Credit Agreement, dated as of August 23, 2010 and effective as of September 10, 2010, among Carrizo Oil & Gas, Inc., as Borrower, certain Subsidiaries of the Borrower, as  Guarantors, the Lenders party thereto, and Wells Fargo  Bank, N.A., as administrative agent and issuing bank.
10.2	Amendment No. 1, dated as of August 4, 2010, to the Participation Agreement among Carrizo (Marcellus) LLC, Carrizo Oil & Gas, Inc., Avista Capital Partners II, L.P. and ACP II Marcellus LLC, effective as of August 1, 2008.
10.3	Omnibus Amendment among Carrizo (Marcellus) LLC, Carrizo Oil & Gas, Inc., Avista Capital Partners II, L.P. and ACP II Marcellus LLC, dated as of September 10, 2010.

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.

CARRIZO OIL & GAS, INC.
By:	/s/ Paul F. Boling
Name:	Paul F. Boling
Title	Vice President and
	Chief Financial Officer

Date:  September 16, 2010

Exhibit Index

Exhibit                                Description

10.1 Thirteenth Amendment to Credit Agreement, dated as of August 23, 2010 and effective as of September 10, 2010, among Carrizo Oil & Gas, Inc., as Borrower, certain Subsidiaries of the Borrower, as  Guarantors, the Lenders party thereto, and Wells Fargo  Bank, N.A., as administrative agent and issuing bank.

10.2 Amendment No. 1, dated as of August 4, 2010, to the Participation Agreement among Carrizo (Marcellus) LLC, Carrizo Oil & Gas, Inc., Avista Capital Partners II, L.P. and ACP II Marcellus LLC, effective as of August 1, 2008.

10.3 Omnibus Amendment among Carrizo (Marcellus) LLC, Carrizo Oil & Gas, Inc., Avista Capital Partners II, L.P. and ACP II Marcellus LLC, dated as of September 10, 2010.

EX-10.1

EXHIBIT 10.1

EXECUTION VERSION

THIRTEENTH AMENDMENT TO CREDIT AGREEMENT

THIRTEENTH AMENDMENT TO CREDIT AGREEMENT (this “Amendment”) dated as of August 23, 2010, by and among CARRIZO OIL & GAS, INC., a Texas corporation (“Borrower”), certain SUBSIDIARIES OF BORROWER, as Guarantors (in such capacity, “Guarantors”), the LENDERS party hereto (the “Lenders”), and WELLS FARGO BANK, N.A., as administrative agent for the Lenders (in such capacity, the “Administrative Agent”).& #160; Unless otherwise expressly defined herein, capitalized terms used but not defined in this Amendment have the meanings assigned to such terms in the Credit Agreement (as defined below).

WITNESSETH:

WHEREAS, Borrower, Guarantors, Administrative Agentand Lenders are party to that certain Credit Agreement, dated as of May 25, 2006 (as the same has been and may hereafter be amended, restated, supplemented or otherwise modified from time to time, the “Credit Agreement”); and

WHEREAS, Borrower, Guarantors, Administrative Agent and Lenders have agreed to amend the Credit Agreement as provided herein subject to the terms and conditions set forth herein.

NOW, THEREFORE, for and in consideration of the mutual covenants and agreements herein contained and other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged and confessed, the parties hereto hereby agree as follows:

SECTION 1.Amendments to Credit Agreement.  Subject to the satisfaction or waiver in writing of each condition precedent set forth in Section 3 of this Amendment, and in reliance on the representations, warranties, covenants and agreements contained in this Amendment, the Credit Agreement shall be amended in the manner provided in this Section 1.

1.1Additional Definitions.  The following definitions shall be and they hereby are added to Section 1.01 of the Credit Agreement in appropriate alphabetical order:

“Reliance” means Reliance Marcellus II, LLC, a Delaware limited liability company, and its successors and permitted assigns.

“Reliance Joint Venture” means that certain joint venture arrangement between Carrizo Marcellus and Reliance in respect of the exploration, development and production of the Reliance JV Oil and Gas Properties; provided that such joint venture arrangement is governed by the Reliance JV Documents.

“Reliance JV Documents” means the Reliance JV Operating Agreement, the Reliance JV Participation Agreement and any other documents, agreements and instruments governing the Reliance Joint Venture, in each case, as the same may be amended, modified or supplemented from time to time to the extent permitted hereunder.

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“Reliance JV Oil and Gas Properties” means the leasehold acreage and other oil and gas interests located within Pennsylvania that are subject to the Reliance JV Documents and in which both Carrizo Marcellus and Reliance hold an interest.

“Reliance JV Operating Agreement” means a certain Operating Agreement between Carrizo Marcellus and Reliance relating to the Reliance Joint Venture and containing terms and conditions substantially similar to, and no less favorable to the Lenders than, those set forth in that certain draft Operating Agreement distributed to the Administrative Agent and the Lenders on or about August 17, 2010, as the same may be amended, modified or supplemented from time to time to the extent permitted hereunder.

“Reliance JV Participation Agreement” means a certain Participation and Development Agreement between Carrizo Marcellus and Reliance relating to the Reliance Joint Venture and containing terms and conditions substantially similar to, and no less favorable to the Lenders than, those set forth in that certain draft Participation and Development Agreement distributed to the Administrative Agent and the Lenders on or about August 17, 2010, as the same may be amended, modified or supplemented from time to time to the extent permitted hereunder.

“Reliance JV Principal Documents” means the Reliance JV Operating Agreement and the Reliance JV Participation Agreement, in each case, as the same may be amended, modified or supplemented from time to time to the extent permitted hereunder.

1.2Notices of Material Events.  Section 6.02 of the Credit Agreement shall be and it hereby is amended by (a) deleting the “and” located at the end of clause (d) thereof, (b) relettering clause (e) as clause (f), and (c) adding a new clause (e) to read as follows:

(e) the occurrence of any material breach or material default under, or repudiation or termination of, or the receipt or delivery of any written notice of any material default or material claim under, any Reliance JV Document by any party thereto, including, without limitation, the receipt or delivery of (i) any Default Notice under and as defined in Section 8.1 of the Reliance JV Operating Agreement and (ii) any written notice of default under Section 8.1 of the Reliance JV Participation Agreement; and

1.3Reliance JV Documents.  Article VI of the Credit Agreement shall be and it hereby is amended by adding a new Section 6.17 to the end thereof to read as follows:

Section 6.17. Reliance JV Documents.  The Borrower will provide the Administrative Agent (a) with fully executed copies of any amendments, modifications, supplements or waivers to the Reliance JV Principal Documents promptly, and in any event within thirty (30) days, after execution and delivery thereof and (b) upon the reasonable request of the Administrative Agent, any

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other Reliance JV Document promptly, and in any event within thirty (30) days, after request thereof.

1.4Reliance JV Documents.  Article VII of the Credit Agreement shall be and it hereby is amended by adding a new Section 7.17 to the end thereof to read as follows:

Section 7.17. Reliance JV Documents.  Without the Administrative Agent’s prior written consent, the Borrower will not, nor will it permit any Restricted Subsidiary to, enter into or permit any supplement, modification or amendment of, or waive any right or obligation of any Person under, any Reliance JV Document if the effect thereof would (a) be materially adverse to the Administrative Agent and/or the Lenders, (b) change the definition of “Permitted Pledge” or “Permitted Pledge Transfer” under the Reliance JV Participation Agreement or the Reliance JV Operating Agreement, (c) change Section 6.2 of the Reliance JV Participation Agreement or Section 11.3 of the Reliance JV Operating Agreement, or (d) change any provision of the Reliance JV Participation Agreement or the Reliance JV Operating Agreement that adversely affects the rights of the Administrative Agent or any Lender in respect of a Permitted Pledge or a Permitted Pledge Transfer under and as defined in the Reliance JV Participation Agreement and the Reliance JV Operating Agreement, respectively.

SECTION 2.Consent.  Each Lender hereby consents to the terms and conditions of, and authorizes the Administrative Agent to execute and deliver, those certain Pledge Agreement amendments in substantially the forms attached as Annex A and Annex B to this Amendment.

SECTION 3.Conditions.  Provided that such conditions are satisfied on or before November 30, 2010, the amendments to the Credit Agreement contained in Section 1 of this Amendment and the consents contained in Section 2 of this Amendment shall be effective upon the satisfaction of each of the conditions set forth in this Section 3.

3.1Execution and Delivery.  Each Credit Party, the Required Lenders, and the Administrative Agent shall have executed and delivered this Amendment.

3.2Reliance Joint Venture.  The Administrative Agent shall have received evidence reasonably satisfactory to it that substantially contemporaneous with the effectiveness of this Amendment, the Reliance JV Participation Agreement and Reliance JV Operating Agreement shall have become effective.

3.3No Default.  No Default shall have occurred and be continuing or shall result from the effectiveness of this Amendment.

3.4Other Documents.  The Administrative Agent shall have received such other instruments and documents incidental and appropriate to the transaction provided for herein as the Administrative Agent or its special counsel may reasonably request prior to the date hereof, and all such documents shall be in form and substance reasonably satisfactory to the Administrative Agent.

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SECTION 4.Representations and Warranties of the Credit Parties.  To induce the Lenders to enter into this Amendment, each Credit Party hereby represents and warrants to the Lenders as follows:

4.1Reaffirmation of Representations and Warranties/Further Assurances.  After giving effect to the amendments herein, each representation and warranty of such Credit Party contained in the Credit Agreement or in any of the other Loan Documents is true and correct in all material respects as of the date hereof (except to the extent such representations and warranties specifically refer to an earlier date, in which case such representations and warranties shall be true and correct in all material respects as of such earlier date and taking into account any amendments to the schedules or exhibits as a result of any disclosures made in writing by such Credit Party to the Administrative Agent after the Effective Date and approved by the Administrative Agent and the Required Lenders in writing).

4.2Corporate Authority; No Conflicts.  The execution, delivery and performance by such Credit Party (to the extent a party hereto or thereto) of this Amendment and all documents, instruments and agreements contemplated herein are within such Credit Party’s corporate or other organizational powers, have been duly authorized by all necessary action, require no action by or in respect of, or filing with, any court or agency of government and do not violate or constitute a default under any provision of any applicable law or other agreements binding upon such Credit Party or result in the creation or imposition of any Lien upo n any of the assets of such Credit Party except for Permitted Liens and otherwise as permitted in the Credit Agreement.

4.3Enforceability.  This Amendment constitutes the valid and binding obligation of such Credit Party enforceable in accordance with its terms, except as (i) the enforceability thereof may be limited by bankruptcy, insolvency or similar laws affecting creditor’s rights generally and (ii) the availability of equitable remedies may be limited by equitable principles of general application.

4.4No Default.  As of the date hereof, both before and immediately after giving effect to this Amendment, no Default or Event of Default has occurred and is continuing.

SECTION 5.Miscellaneous.

5.1Reaffirmation of Loan Documents and Liens.  Any and all of the terms and provisions of the Credit Agreement and the Loan Documents shall, except as amended and modified hereby, remain in full force and effect and are hereby in all respects ratified and confirmed by each Credit Party.  Each Credit Party hereby agrees that nothing contained in this Amendment shall in any manner affect or impair the liabilities, duties and obligations of such Credit Party under the Credit Agreement and the other Loan Documents or the Liens securing the payment and performance thereof.

5.2Parties in Interest.  All of the terms and provisions of this Amendment shall bind and inure to the benefit of the parties hereto and their respective successors and assigns.

5.3Legal Expenses.  The Borrower hereby agrees to pay all reasonable fees and expenses of special counsel to the Administrative Agent incurred by the Administrative Agent in

Thirteenth Amendment to Credit Agreement - Page 4

connection with the preparation, negotiation and execution of this Amendment and all related documents.

5.4Counterparts.  This Amendment may be executed in one or more counterparts and by different parties hereto in separate counterparts each of which when so executed and delivered shall be deemed an original, but all such counterparts together shall constitute but one and the same instrument; signature pages may be detached from multiple separate counterparts and attached to a single counterpart so that all signature pages are physically attached to the same document.  Delivery of photocopies of the signature pages to this Amendment by facsimile or electronic mail shall be effective as delivery of manually executed coun terparts of this Amendment.

5.5Headings.  The headings, captions and arrangements used in this Amendment are, unless specified otherwise, for convenience only and shall not be deemed to limit, amplify or modify the terms of this Amendment, nor affect the meaning thereof.

5.6Governing Law.  This Amendment shall be construed in accordance with and governed by the law of the State of Texas.

5.7Severability.  Any provision of this Amendment held to be invalid, illegal or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such invalidity, illegality or unenforceability without affecting the validity, legality and enforceability of the remaining provisions hereof; and the invalidity of a particular provision in a particular jurisdiction shall not invalidate such provision in any other jurisdiction.

5.8Complete Agreement.  THIS AMENDMENT, THE CREDIT AGREEMENT, AND THE OTHER LOAN DOCUMENTS REPRESENT THE FINAL AGREEMENT AMONG THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS OR ORAL AGREEMENTS OF THE PARTIES.  THERE ARE NO UNWRITTEN ORAL AGREEMENTS AMONG THE PARTIES.

[Signature Page Follows]

Thirteenth Amendment to Credit Agreement - Page 5

IN WITNESS WHEREOF, the parties have caused this Amendment to be duly executed by their respective authorized officers to be effective as of the date first above written.

BORROWER:
CARRIZO OIL & GAS, INC.
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President and Chief Financial Officer

GUARANTORS:
CCBM, INC.
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President

CLLR, INC.
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President

HONDO PIPELINE, INC.
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President

CARRIZO (MARCELLUS) LLC
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President

Thirteenth Amendment to Credit Agreement

Signature Page

CARRIZO MARCELLUS HOLDING INC.
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President

CHAMA PIPELINE HOLDING LLC
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President

BANDELIER PIPELINE HOLDING, LLC
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President

MESCALERO PIPELINE, LLC
By:	/s/Paul F. Boling
Name:	Paul F. Boling
Title :	Vice President

Thirteenth Amendment to Credit Agreement

Signature Page

WELLS FARGO BANK, N.A., as
Administrative Agent, Issuing Bank and as a
Lender
By:	/s/Scott Hodges
Name:	Scott Hodges
Title :	Director

Thirteenth Amendment to Credit Agreement

Signature Page

ROYAL BANK OF CANADA,
as a Co-Syndication Agent and as a Lender
By:	/s/Don J. McKinnerney
Name:	Don J. McKinnerney
Title :	Authorized Secretary

Thirteenth Amendment to Credit Agreement

Signature Page

CREDIT AGRICOLE CORPORATE AND
INVESTMENT BANK (f/k/a CALYON NEW
YORK BRANCH), as a Co-Syndication Agent and
as a Lender
By:	/s/Tim Byargeon
Name:	Tim Byargeon
Title :	Managing Director

By:	/s/Michael D. Willis
Name:	Michael D. Willis
Title :	Managing Director

Thirteenth Amendment to Credit Agreement

Signature Page

CAPITAL ONE, N.A.,
as Documentation Agent and as a Lender
By:	/s/Paul D. Hein
Name:	Paul D. Hein
Title :	Vice President

Thirteenth Amendment to Credit Agreement

Signature Page

UNION BANK, N.A. (f/k/a UNION BANK
OF CALIFORNIA, N.A.),
as a Lender
By:	/s/Timothy Brendel
Name:	Timothy Brendel
Title :	Vice President

Thirteenth Amendment to Credit Agreement

Signature Page

U.S. BANK NATIONAL ASSOCIATION,
as a Lender
By:	/s/John C. Lozano
Name:	John C. Lozano
Title :	Vice President

Thirteenth Amendment to Credit Agreement

Signature Page

CREDIT SUISSE AG, CAYMAN ISLANDS
BRANCH,
as a Lender
By:	/s/Mikhail Faybusovich
Name:	Mikhail Faybusovich
Title :	Vice President

By:	/s/Vipul Dhadda
Name:	Vipul Dhadda
Title :	Associate

Thirteenth Amendment to Credit Agreement

Signature Page

COMPASS BANK (as successor in interest to
Guaranty Bank),as a Lender
By:	/s/Kathleen J. Bowen
Name:	Kathleen J. Bowen
Title :	Senior Vice President

Thirteenth Amendment to Credit Agreement

Signature Page

FORTIS CAPITAL CORP.,
as a Lender
By:	/s/Betsy Jocher
Name:	Betsy Jocher
Title :	Director

By:	/s/Greg Smothers
Name:	Vipul Dhadda
Title :	Director

Thirteenth Amendment to Credit Agreement

Signature Page

COMPASS BANK,as a Lender
By:	/s/Kathleen J. Bowen
Name:	Kathleen J. Bowen
Title :	Senior Vice President

Thirteenth Amendment to Credit Agreement

Signature Page

EX-10.2

Exhibit 10.2

AMENDMENT NO. 1 TO PARTICIPATION AGREEMENT

THIS AMENDMENT NO. 1, dated as of August 4, 2010 (this “Amendment”) to the Participation Agreement, effective as of August 1, 2008 (the “Agreement”), is entered into among Carrizo (Marcellus) LLC, a Delaware limited liability company (“Carrizo”), Carrizo Oil & Gas, Inc., a Texas corporation (“COGI” and, together with Carrizo, the “Carrizo Parties”), Avista Capital Partners II, L.P., a Delaware limited partnership (“Avista”), and A CP II Marcellus LLC, a Delaware limited liability company (“Investor LLC” and, together with Avista, the “Avista Parties”).  In this Agreement, Carrizo, COGI, Avista and Investor LLC are collectively referred to as the “Parties” and each as a “Party.”

RECITALS:

A.           The Carrizo Parties and Investor LLC entered into the Agreement, among other things, to dedicate their respective interests in certain Oil and Gas Interests for the mutual benefit of Carrizo and Investor LLC.

B.           Concurrently with the execution of this Amendment, the Carrizo Parties and Investor LLC are entering into purchase and sale agreements providing for the sale by them to Reliance Marcellus II, LLC (“Reliance”) of a substantial portion of the Properties.

C.           The Parties desire to amend the Agreement in connection with the transactions with Reliance, including with respect to the Participation and Development Agreement to be entered into by Carrizo and Reliance in connection with the closing of sale of Carrizo’s interests in certain Properties to Reliance.

NOW, THEREFORE, for good and valuable consideration, the receipt and sufficiency of which is hereby acknowledged, the Parties agree as follows:

SECTION 1.  DEFINITIONS.

(a)Capitalized terms used but not defined in this Amendment have the meanings given to them in the Agreement.

(b)Article 1 of the Agreement is amended by deleting the following defined terms therefrom:  Equity Purchase Rights, Equity ROFR Initiator, Qualifying Equity Interests, Qualifying Equity Transfer and Selling Member.

(c)Article 1 of the Agreement is further amended by adding the following defined terms:

“Carrizo-Reliance Purchase and Sale Agreement” means the Purchase and Sale Agreement among the Carrizo Parties, Monument Exploration, LLC, Reliance and Reliance Holding USA, Inc. dated as of August 2, 2010.

“Investor LLC-Reliance Purchase and Sale Agreement” means the Purchase and Sale Agreement among Investor LLC, Reliance and Reliance Holding USA, Inc. dated as of August 2, 2010.

“Reliance Purchase and Sale Agreements” means the Carrizo-Reliance Purchase and Sale Agreement and the Investor LLC-Reliance Purchase and Sale Agreement.

(d)The definition of “Permitted Pledge” is amended by deleting the reference to Section 4.2(b) therefrom.

SECTION 2.  AMENDMENTS.

(a)Section 3.1 of the Agreement is amended by adding the following provision to the end of such section:

Following the Closing (as defined respectively in each Reliance Purchase and Sale Agreement) pursuant to the Reliance Purchase and Sale Agreements and subject to Section 3.3, Net Cash Flow From Production shall be allocated between Investor LLC and Carrizo pursuant to Section 3.1(c).

(b)Section 3.2 of the Agreement is amended by adding the following provision to the end of such section:

Following the Closing (as defined respectively in each Reliance Purchase and Sale Agreement) pursuant to the Reliance Purchase and Sale Agreements and subject to Section 3.3, proceeds received from the Transfer of any Oil and Gas Interest in the Properties shall be allocated between Investor LLC and Carrizo pursuant to Section 3.2(c).

(c)Section 3.3 of the Agreement is amended by adding the following provisions to the end of such section:

Proceeds from any Transfer of Oil and Gas Interests in the Properties by Investor LLC under the Investor LLC-Reliance Purchase and Sale Agreement shall be allocated 100% to Investor LLC.  Proceeds from any Transfer of Oil and Gas Interests in the Properties by Carrizo under the Carrizo-Reliance Purchase and Sale Agreement shall be allocated 100% to Carrizo.  Following the Closing (as defined respectively in each Reliance Purchase and Sale Agreement), Investor LLC agrees to pay, from the proceeds received pursuant to the Investor LLC-Reliance Purchase and Sale Agreement, Carrizo any outstanding obligations of Investor LLC owed to Carrizo or its Affiliates under the Operating Agreement within five (5) Business Days of Investor LLC’s receipt of invoices (together with reasonable supporting documentation) therefor from Carrizo.

(d)Sections 4.1(a), 4.1(b) and 4.3(b) of the Agreement are amended by deleting the references to Section 4.2(b) therefrom.

(e)           The following provision is added to Section 4.1(a):

2

If, following the Closing (as defined respectively in each Reliance Purchase and Sale Agreement), all or substantially all of Carrizo’s Oil and Gas Interests in the Properties are transferred to an Affiliate, the Parties agree in connection therewith to reinstate a mutual right of first refusal with respect to the equity interests in such transferee and Investor LLC similar to that in Section 4.2(b) of the Agreement, as it existed prior to this Amendment.

(f)           Section 4.2(b) of the Agreement is deleted.

SECTION 3.  TERMINATION OF THE RELIANCE PURCHASE AND SALE AGREEMENTS.  If, prior to the Closing (as defined respectively in each Reliance Purchase and Sale Agreement), the Reliance Purchase and Sale Agreements are terminated for any reason, this Amendment shall automatically be deemed null and void, and of no further force and effect, without the need for further act or evidence.

SECTION 4.  EFFECT ON THE AGREEMENT.  Except as specifically provided above, the Agreement shall continue to be in full force and effect.

SECTION 5.  COUNTERPARTS.  This Amendment may be executed in counterparts, and by different Parties in separate counterparts, each of which shall be deemed an original instrument, but all such counterparts together shall constitute one amendment.

SECTION 6.  GOVERNING LAW.  This Amendment and the legal relations between the Parties shall be governed by and construed in accordance with the Laws of the State of Texas, USA without regard to principles of conflicts of Laws.

 [Signature Page Follows]

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IN WITNESS WHEREOF, the Parties have caused this Amendment to be executed as of the date first above written.

ACP II MARCELLUS LLC	CARRIZO OIL & GAS, INC.
By:           ACP II AMS LP,
its Manager	By:      /s/Paul F. Boling
	Paul F. Boling
By:    Avista Capital Partners II, L.P.,	Vice President, Chief Financial
its General Partner	Officer and Secretary
By:    Avista Capital Partners II GP, LLC	CARRIZO (MARCELLUS) LLC
its General Partner
By:    /s/Robert L. Cabes, Jr.	By:      /s/Paul F. Boling
Robert L. Cabes, Jr.	Paul F. Boling
Partner	Vice President, Chief Financial
	Officer and Secretary
AVISTA CAPITAL PARTNERS II, L.P.
By:    Avista Capital Partners II GP, LLC,
its General Partner
By:    /s/Robert L. Cabes, Jr.
Robert L. Cabes, Jr.
Partner

EX-10.3

Execution Version

OMNIBUS AMENDMENT

This Omnibus Amendment (this “Amendment”) is made and entered into on September 10, 2010 (the “Effective Date”), by and among Carrizo (Marcellus) LLC, a Delaware limited liability company (“Carrizo Marcellus”), Carrizo Oil & Gas, Inc., a Texas corporation (“COGI” and, together with Carrizo Marcellus, the “Carrizo Parties”), Avista Capital Partners II, L.P., a Delaware limited partnership (“ACP”), and ACP II Marcellus LLC, a Delaware limited liability company (“Avista” and, together with ACP, the “Avista Parties”).  Carrizo Marcellus, COGI, ACP and Avista are sometimes hereinafter referred to individually as a “Party” and collectively as the “Parties.”

RECITALS

WHEREAS, as of August 4, 2010, the Carrizo Parties, Monument Exploration, LLC, a Texas limited liability company (“Monument”) and Reliance Marcellus II, LLC, a Delaware limited liability company (“Reliance”) have entered into that certain Purchase and Sale Agreement, as amended, pursuant to which the Carrizo Parties and Monument are conveying to Reliance, as of the Effective Date, the right, title and interest held by the Carrizo Parties and Monument in the “Properties” (as defined therein and hereinafter referred to as the “Properties I”);

WHEREAS, as of August 4, 2010, Avista and Reliance have entered into that certain Purchase and Sale Agreement (the “Avista PSA”), pursuant to which Avista is conveying to Reliance, as of the Effective Date, the right, title and interest held by Avista in the “Properties” (as defined therein and hereinafter referred to as the “Properties II” and, together with the Properties I, the “Reliance Properties”; provided that any Properties I or Properties II not conveyed to Reliance pursuant to the above-referenced Purchase and Sale Agreements shall not be “Reliance Properties” unless and until they are so conveyed and any Properties I or Properties II shall cease to be “Reliance Properties” at such time as such properties are reconveyed by Reliance pursuant to the above-referenced Purchase and Sale Agreements);

WHEREAS, concurrently with the execution hereof, Carrizo Marcellus and Reliance are entering into the Participation and Development Agreement providing for, among other things, their participation together in the exploration and development of the “Joint Interests” (as defined therein and hereinafter referred to as the “PDA Interests”) in a coordinated manner;

WHEREAS, the Parties desire to amend the Subject Agreements (as hereinafter defined) such that the Reliance Properties and the other PDA Interests are no longer subject to, or encumbered by, the Subject Agreements.

NOW, THEREFORE, for and in consideration of the mutual promises contained herein, the benefits to be delivered by each Party hereunder, and the other good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged, the Parties agree as follows:

ARTICLE I

RELEASE OF THE PROPERTIES

1.1The Parties hereby acknowledge and agree that:

1.1.1As of the Effective Date, (a) the Reliance Properties and the other PDA Interests are hereby released from the Subject Agreements and (b) the Subject Agreements are hereby amended such that the Reliance Properties and the other PDA Interests are no longer subject to, or encumbered by, the Subject Agreements;

1.1.2The definition of “AMI” in the Subject Agreements is hereby amended to exclude all of the Commonwealth of Pennsylvania; provided, however, that notwithstanding the foregoing, until the Cure Deadline (as defined in the Avista PSA), the AMI shall include all Qualified Acreage (as defined in the Avista PSA) to the extent such would otherwise be subject to the AMI without giving effect to this amendment to the definition of that term if Avista determines to exercise its rights to provide Qualified Acreage under the Avista PSA to cure a Title Defect (as defined in the Avista PSA);

1.1.3Reliance has no rights, duties or obligations under the Subject Agreements; and

1.1.4The Parties shall execute and record evidence of this Amendment in the appropriate public records, at their sole cost and expense, with respect to any Subject Agreement that has been previously so recorded.

ARTICLE II

MISCELLANEOUS

2.1Defined Terms.  The following term shall have the indicated meaning:

“Subject Agreements” means the following agreements: (a) that certain Participation Agreement (the “Participation Agreement”), effective as of August 1, 2008, among the Carrizo Parties and the Avista Parties; (b) that certain Operating Agreement, effective as of August 1, 2008, between Carrizo Marcellus and Avista; (c) that certain Management Services Agreement, dated as of November 3, 2008, between Avista and COGI; and (d) any other agreements related to, or associated with, the agreements described in (a)-(c) of this definition (as such agreements may be amended, extended or renewed) between any of the Carrizo Parties, or any of their affiliates, on the one ha nd, and any of the Avista Parties, or any of their affiliates, on the other hand that bind or restrict the Reliance Properties or the other PDA Interests.

2.2Prior Transfers.  The terms and provisions of this Amendment do not affect any transfers, assignments or conveyances by any of the Carrizo Parties on the one hand, and any of the Avista Parties on the other, prior to the Effective Date and pursuant to the Subject Agreements.

2.3Binding.  Except as modified and amended by this Amendment, all of the terms, covenants and conditions of the Subject Agreements are hereby ratified and confirmed and shall remain in full force and effect.

2.4Further Assurances.  In case at any time after the Effective Date any further action is necessary or desirable to carry out the purposes of this Amendment, each of the Parties will take such further action (including the execution and delivery of such further instruments and documents) as any other Party or Reliance may reasonably request.

2.5Governing Law.  This Amendment shall be governed by and construed and interpreted in accordance with the laws of the State of Texas (except that, with respect to issues relating to title to real property located in Pennsylvania, the laws of the Commonwealth of Pennsylvania shall govern), excluding any conflicts of law rule or principle that might refer to the laws of another jurisdiction.

2.6Successors and Assigns.  This Amendment shall be binding upon and shall inure to the benefit of the Parties and their respective successors and permitted assigns.

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2.7Counterparts.  This Amendment may be executed in counterparts, and by different Parties in separate counterparts, each of which shall be deemed an original instrument, but all such counterparts together shall constitute one agreement.

2.8Severability.  If any provision of this Amendment is held invalid or unenforceable, all other provisions will not be affected.  With respect to the provisions held invalid or unenforceable, the Parties will, to the fullest extent allowed by law, amend or modify this Amendment as necessary to effect the original intent of the Parties.

2.9Tax Treatment. For purposes of federal income taxation and for purposes of any applicable state or local income tax that incorporate or follow federal income tax principles (“Tax Purposes”) the Parties agree to treat this Amendment as effecting a pro-rata (50% each) distribution of the PDA Interests from the partnership currently existing between the Carrizo Parties and the Avista Parties solely for Tax Purposes pursuant to Exhibit 8.1 of the Participation Agreement (the “Tax Partnership ”) to the Carrizo Parties, on the one hand, and the Avista Parties, on the other, occurring immediately prior to the Effective Date, the intent of the Parties being that the conveyances to Reliance of the Reliance Properties shall be treated for Tax Purposes as conveyances of direct, undivided interests in such properties rather than conveyances of interests in the Tax Partnership.

Signature Page Follows.

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IN WITNESS WHEREOF, the Parties have caused this Amendment to be executed as of the Effective Date.

ACP II MARCELLUS LLC	CARRIZO OIL & GAS, INC.
By:           ACP II AMS LP, its Manager	By:/s/Gerry Morton
	Gerry Morton
	General Counsel and Vice President of
	Business Development
By: Avista Capital Partners II, L.P.,
its General Partner
By:  Avista Capital Partners II GP, LLC	CARRIZO (MARCELLUS) LLC
its General Partner
By:  /s/Robert Cabes	By: /s/Gerry Morton
Name:  Robert Cabes	Gerry Morton
Title:    Authorized Secretary	Vice President and Assistant Secretary
AVISTA CAPITAL PARTNERS II, L.P.
By:  Avista Capital Partners II GP, LLC
its General Partner
By: /s/Robert Cabes
Name:  Robert Cabes
Title:  Authorized Secretary

Signature Page to Omnibus Amendment