8-K

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, DC 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): April 30, 2012

Atlas Resource Partners, L.P.

(Exact name of registrant as specified in its chapter)

Delaware	1-35317	45-3591625
(State or other jurisdiction of incorporation)	(Commission File Number)	(IRS Employer Identification No.)

Park Place Corporate Center One 1000 Commerce Drive, Suite 400 Pittsburgh, PA	15275
(Address of principal executive offices)	(Zip Code)

Registrant’s telephone number, including area code: 800-251-0171

(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 (see General Instruction A.2. below):

¨ 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.

Credit Agreement

On April 30, 2012, Atlas Resources Partners, L.P. (the “Partnership”) entered into an amendment to its senior secured revolving credit facility (the “Credit Facility”) to increase the borrowing base from $138 million to $250 million. This borrowing base redetermination was in lieu of the redetermination scheduled for May 1, 2012. The amendment also effected a modification in the applicable margin used to calculate interest under the Credit Facility to between 2.00% and 3.00% for LIBOR loans and between 1.00% and 2.00% for base rate loans. The Partnership borrowed $67 million under the Credit Facility to partially fund the Acquisition (defined below). A copy of the First Amendment to Amended and Restated Credit Agreement is attached hereto as Exhibit 10.1.

Sale of Common Units

Also on April 30, 2012, the Partnership completed its previously announced private placement (the “Private Placement”) of its common units pursuant to the Common Unit Purchase Agreement dated March 15, 2012 (the “Common Unit Purchase Agreement”), between the Partnership and the third party investors named therein (collectively the “Purchasers”). In accordance with the Common Unit Purchase Agreement, which was filed by the Partnership as Exhibit 10.1 to its Current Report on Form 8-K filed on March 21, 2012, the Partnership issued 6,027,945 of its common units at a negotiated price per unit of $20.00, resulting in gross proceeds to the Partnership of $120,558,900. $5 million of common units were purchased by executive officers of the general partner of the Partnership. The proceeds were used to partially fund the Acquisition. The common units were issued and sold in a private transaction exempt from registration under Section 4(2) of the Securities Act of 1933, as amended.

In connection with the Private Placement, the Partnership entered into a Registration Rights Agreement (the “Registration Rights Agreement”) pursuant to which the Partnership agreed to file a registration statement with the Securities and Exchange Commission within 6 months of April 30, 2012 to register the resale of the common units by the Purchasers. In accordance with the Registration Rights Agreement, the Partnership will use its commercially reasonable efforts to have the registration statement declared effective by December 31, 2012, and will cause the registration statement to be continuously effective until the earlier of (i) the date as of which all such common units registered thereunder are sold by the Purchasers and (ii) April 30, 2013. This summary of the Registration Rights Agreement does not purport to be complete and is qualified in its entirety by reference to the Registration Rights Agreement, a copy of which is attached hereto as Exhibit 4.1.

Item 2.01. Completion of Acquisition or Disposition of Assets.

On April 30, 2012, ARP Barnett, LLC, an indirect wholly-owned subsidiary of the Partnership (“ARP Barnett”), completed the acquisition (the “Acquisition”) of certain assets from Carrizo Oil & Gas, Inc. and its wholly owned subsidiaries CLLR Inc., Hondo Pipeline, Inc. and Mescalero Pipeline, LLC pursuant to the Purchase and Sale Agreement dated as of March 15, 2012, for $187 million in cash. The Purchase and Sale Agreement was filed by the Partnership as Exhibit 2.1 to its Current Report on Form 8-K filed on March 21, 2012. The assets acquired include interests in approximately 200 natural gas wells producing from the Barnett Shale, located in Bend Arch-Fort Worth Basin in North Texas and related proved undeveloped acres as well as gathering pipelines and associated gathering facilities that service certain of the acquired wells.

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Item 2.03. Creation of a Direct Financial Obligation or an Obligation under an Off-Balance Sheet Arrangement of a Registrant.

The information set forth under Item 1.01 above is incorporated herein by reference.

Item 3.02 Unregistered Sales of Equity Securities.

The disclosure set forth above under Item 1.01 to this Current Report is hereby incorporated by reference into this Item 3.02.

Item 7.01 Regulation FD Disclosure.

On April 30, 2012, Atlas issued a press release related to the foregoing. A copy of the press release is attached as Exhibit 99.1 to this Current Report on Form 8-K.

Item 8.01. Other Events.

On April 18, 2012, the Partnership’s newly-formed subsidiaries, ARP Barnett and ARP Oklahoma, LLC, joined as guarantors of the Credit Facility. On April 30, 2012, the Partnership’s newly-formed subsidiary, ARP Barnett Pipeline, LLC, joined as a guarantor of the Credit Facility. Copies of the Joinder Agreements are attached hereto as Exhibit 10.2 and 10.3.

Historical financial statements for the businesses acquired and pro forma financial information are not included in this Current Report on Form 8-K. This information will be filed in a subsequent Current Report on Form 8-K as required by Securities and Exchange Commission regulations.

Item 9.01. Financial Statements and Exhibits.

(d) Exhibits

4.1	Registration Rights Agreement dated as of April 30, 2012
10.1	First Amendment to Amended and Restated Credit Agreement dated as of April 30, 2012
10.2	Joinder Agreement dated as of April 18, 2012
10.3	Joinder Agreement dated as of April 30, 2012
99.1	Press Release of Atlas Resource Partners, L.P. dated as of April 30, 2012.

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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 thereunto duly authorized.

Dated: April 30, 2012	ATLAS RESOURCE PARTNERS, L.P.
	By:	Atlas Resource Partners GP, LLC, its general partner
	By:	/s/ Sean P. McGrath
	Name:	Sean P. McGrath
	Its:	Chief Financial Officer

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EX-4.1

Exhibit 4.1

REGISTRATION RIGHTS AGREEMENT

by and among

ATLAS RESOURCE PARTNERS, L.P.

and

THE PURCHASERS NAMED HEREIN

TABLE OF CONTENTS

			Page
Article I      DEFINITIONS		1
Section 1.01	Definitions.		1
Section 1.02	Registrable Securities.		3
Article II      REGISTRATION RIGHTS		3
Section 2.01	Registration.		3
Section 2.02	Piggyback Rights.		5
Section 2.03	Underwritten Offering.		7
Section 2.04	Sale Procedures.		8
Section 2.05	Cooperation by Holders.		11
Section 2.06	Restrictions on Public Sale by Holders of Registrable Securities.		12
Section 2.07	Expenses.		12
Section 2.08	Indemnification.		12
Section 2.09	Rule 144 Reporting.		14
Section 2.10	Transfer or Assignment of Registration Rights.		15
Section 2.11	Limitation on Subsequent Registration Rights.		15
Article III      MISCELLANEOUS		15
Section 3.01	Communications.		15
Section 3.02	Successor and Assigns.		16
Section 3.03	Aggregation of Purchased Units.		16
Section 3.04	Recapitalization, Exchanges, Etc. Affecting the Units.		16
Section 3.05	Change of Control.		16
Section 3.06	Specific Performance.		16
Section 3.07	Counterparts.		16
Section 3.08	Headings.		16
Section 3.09	Governing Law.		16
Section 3.10	Severability of Provisions.		16
Section 3.11	Entire Agreement.		17
Section 3.12	Amendment.		17
Section 3.13	No Presumption.		17
Section 3.14	Obligations Limited to Parties to Agreement.		17

REGISTRATION RIGHTS AGREEMENT

THIS REGISTRATION RIGHTS AGREEMENT (this “Agreement”) is made and entered into as of April 30, 2012, by and among Atlas Resource Partners, L.P., a Delaware limited partnership (“Atlas”), and each of the Purchasers set forth in Exhibit A (each, a “Purchaser” and, collectively, the “Purchasers”).

WHEREAS, this Agreement is made in connection with the Closing of the issuance and sale of the Purchased Units pursuant to the Common Unit Purchase Agreement, dated as of March 15, 2012, by and among Atlas and the Purchasers (the “Purchase Agreement”);

WHEREAS, Atlas has agreed to provide the registration and other rights set forth in this Agreement for the benefit of the Purchasers pursuant to the Purchase Agreement; and

WHEREAS, it is a condition to the obligations of each Purchaser and Atlas under the Purchase Agreement that this Agreement be executed and delivered.

NOW THEREFORE, in consideration of the mutual covenants and agreements set forth herein and for good and valuable consideration, the receipt and sufficiency of which are hereby acknowledged by each party hereto, the parties hereby agree as follows:

ARTICLE I

DEFINITIONS

Section 1.01 Definitions. Capitalized terms used herein without definition shall have the meanings given to them in the Purchase Agreement. The terms set forth below are used herein as so defined:

“Agreement” has the meaning specified therefor in the introductory paragraph.

“Atlas” has the meaning specified therefor in the introductory paragraph.

“Effectiveness Period” has the meaning specified therefor in Section 2.01(a)(i) of this Agreement.

“File Date” has the meaning specified therefor in Section 2.01(a)(i) of this Agreement.

“Holder” means a holder, directly or indirectly, including pursuant to a total return swap or similar transaction, of any Registrable Securities; provided, however, that no indirect holder shall be deemed to be a Holder unless and until the record holder and such indirect holder provide notice to Atlas that such indirect holder shall be deemed to be the Holder for purposes hereof.

“Included Registrable Securities” has the meaning specified therefor in Section 2.02(a) of this Agreement.

“Liquidated Damages” has the meaning specified therefor in Section 2.01(a)(ii) of this Agreement.

“Liquidated Damages Multiplier” means the product of $20.00 times the number of Purchased Units purchased by such Purchaser.

“Losses” has the meaning specified therefor in Section 2.08 of this Agreement.

“Managing Underwriter” means, with respect to any Underwritten Offering, the book-running lead manager of such Underwritten Offering.

“Opt Out Notice” has the meaning specified therefor in Section 2.02(a) of this Agreement.

“Purchase Agreement” has the meaning specified therefor in the recitals of this Agreement.

“Purchaser” and “Purchasers” have the meanings specified therefor in the introductory paragraph of this Agreement.

“Purchaser Underwriter Registration Statement” has the meaning specified therefor in Section 2.04(n) of this Agreement.

“Registrable Securities” means: (i) the Purchased Units, (ii) any Common Units issued as Liquidated Damages pursuant to this Agreement, and (iii) any Common Units issued pursuant to Section 5.01 of the Purchase Agreement, all of which Registrable Securities are subject to the rights provided herein until such rights terminate pursuant to the provisions hereof.

“Registration Expenses” has the meaning specified therefor in Section 2.07(a) of this Agreement.

“Registration Statement” has the meaning specified therefor in Section 2.01(a)(i) of this Agreement.

“Selling Expenses” has the meaning specified therefor in Section 2.07(a) of this Agreement.

“Selling Holder” means a Holder who is selling Registrable Securities pursuant to a registration statement.

“Target Effective Date” has the meaning specified therefor in Section 2.01(a)(i) of this Agreement.

“Underwritten Offering” means an offering (including an offering pursuant to a Registration Statement) in which Units are sold to an underwriter on a firm commitment basis for reoffering to the public or an offering that is a “bought deal” with one or more investment banks.

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Section 1.02 Registrable Securities. Any Registrable Security will cease to be a Registrable Security when: (a) a registration statement covering such Registrable Security is effective and such Registrable Security has been sold or disposed of pursuant to such effective registration statement; (b) such Registrable Security has been disposed of pursuant to any section of Rule 144 (or any similar provision then in force) under the Securities Act; (c) one year after the Closing Date; (d) such Registrable Security is held by Atlas or one of its Subsidiaries; or (e) such Registrable Security has been sold in a private transaction in which the transferor’s rights under this Agreement are not assigned to the transferee of such securities (but shall not include any such sale or transfer pursuant to a total return swap or similar transaction with respect to such Registrable Security).

ARTICLE II

REGISTRATION RIGHTS

Section 2.01 Registration.

(a) Registration.

(i) Deadline To File and Go Effective. As soon as practicable following the Closing Date, but in any event prior to the date that is six months after the Closing date (the “File Date”), Atlas shall prepare and file a registration statement under the Securities Act to permit the resale of the Registrable Securities from time to time, including as permitted by Rule 415 under the Securities Act (or any similar provision then in force), with respect to all of the Registrable Securities (the “Registration Statement”). With respect to any Registrable Securities owned by a Holder indirectly pursuant to a total return swap or similar transaction, if required under the Securities Act or other applicable law to permit the registration of such Registrable Securities under such Registration Statement, (x) such Holder agrees to unwind such total return swap or similar transaction to the reasonable satisfaction of Atlas or (y) to forego the registration of such Registrable Securities pursuant to such Registration Statement and, in such case, the Registrable Securities of such Holder shall cease to be Registrable Securities for purposes of this Agreement. Atlas shall use its commercially reasonable efforts to cause the Registration Statement to become effective no later than December 31, 2012 (the “Target Effective Date”). A Registration Statement filed pursuant to this Section 2.01 shall be on an S-1 registration form of the Commission (or such other form permissible under the Securities Act). Atlas will use its commercially reasonable efforts to cause the Registration Statement filed pursuant to this Section 2.01 to be continuously effective under the Securities Act until the earlier of (i) the date as of which all such Registrable Securities are sold by the Purchasers and (ii) one year following the Closing Date (the “Effectiveness Period”). The Registration Statement when effective (including the documents incorporated therein by reference) shall comply as to form with all applicable requirements of the Securities Act and the Exchange Act and shall 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 not misleading.

(ii) Failure To Go Effective. If the Registration Statement required by Section 2.01 is not effective by the Target Effective Date, then each Purchaser shall be entitled to a payment with respect to such Purchaser’s Registrable Securities, as liquidated damages and not as a penalty, of 0.50% of the Liquidated Damages Multiplier per 30-day period for the first 30

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days following the Target Effective Date, increasing by an additional 0.50% of the Liquidated Damages Multiplier per 30-day period for each subsequent 30 days, up to a maximum of 2.00% of the Liquidated Damages Multiplier per 30-day period (the “Liquidated Damages”). The Liquidated Damages payable pursuant to the immediately preceding sentence shall be payable within ten Business Days of the end of each such 30-day period. Liquidated Damages for any period of less than 30-days shall be prorated by multiplying Liquidated Damages to be paid in a full 30-day period by a fraction, the numerator of which is the number of days for which Liquidated Damages are owed, and the denominator of which is 30. Any Liquidated Damages shall be paid to each Purchaser in cash or immediately available funds; provided, however, if Atlas certifies that it is unable to pay Liquidated Damages in cash or immediately available funds because such payment would result in a breach under any of Atlas’s or Atlas’s Subsidiaries’ credit facilities or other indebtedness filed as exhibits to the Atlas SEC Documents, then Atlas may pay the Liquidated Damages in kind in the form of the issuance of additional Common Units. Upon any issuance of Common Units as Liquidated Damages, Atlas shall promptly prepare and file an amendment to the Registration Statement prior to its effectiveness adding such Common Units as additional Registrable Securities. The determination of the number of Common Units to be issued as Liquidated Damages shall be equal to the amount of Liquidated Damages divided by the volume weighted average closing price of the Common Units (as reported by The New York Stock Exchange) for the ten trading days immediately preceding the date on which the Liquidated Damages payment is due, less a discount of 2%. Any obligation of Atlas to pay Liquidated Damages (other than Liquidated Damages owing but not yet paid) to a Purchaser shall cease one year following the Closing Date. As soon as practicable following the date that the Registration Statement or any post-effective amendment thereto becomes effective, but in any event within two Business Days of such date, Atlas shall provide the Purchasers with written notice of the effectiveness of the Registration Statement.

(iii) Waiver of Liquidated Damages. If Atlas is unable to cause a Registration Statement to become effective by the Target Effective Date as a result of an acquisition, merger, reorganization, disposition or other similar transaction, then Atlas may request a waiver of the Liquidated Damages, which may be granted or withheld by the consent of the Holders of two-thirds of the aggregate of the Purchased Units in their sole discretion.

(b) Delay Rights. Notwithstanding anything to the contrary contained herein, Atlas may, upon written notice to all of the Selling Holders whose Registrable Securities are included in the Registration Statement, suspend such Selling Holders’ use of any prospectus which is a part of the Registration Statement (in which event each such Selling Holder shall discontinue sales of the Registrable Securities pursuant to the Registration Statement) but such Selling Holder may settle any sales of Registrable Securities, if (i) Atlas is pursuing an acquisition, merger, reorganization, disposition or other similar transaction and Atlas determines in good faith that Atlas’s ability to pursue or consummate such a transaction would be materially adversely affected by any required disclosure of such transaction in the Registration Statement or (ii) Atlas has experienced some other material non-public event, the disclosure of which at such time, in the good faith judgment of Atlas, would materially adversely affect Atlas; provided, however, in no event shall such Selling Holders be suspended under this Section 2.01(b) from selling Registrable Securities pursuant to the Registration Statement for a period that exceeds an aggregate of 30 days in any 90-day period or 90 days in any 365-day period. Upon disclosure of such information or the termination of the condition described above, Atlas shall (i) provide

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prompt notice to the Selling Holders whose Registrable Securities are included in the Registration Statement, (ii) promptly terminate any suspension of sales it has put into effect and (iii) take such other actions to permit sales of Registrable Securities as contemplated in this Agreement.

(c) Additional Rights to Liquidated Damages. If (i) the Holders shall be prohibited from selling their Registrable Securities under the Registration Statement as a result of a suspension pursuant to Section 2.01(b) of this Agreement in excess of the periods permitted therein or (ii) the Registration Statement is filed and effective but, during the Effectiveness Period, shall thereafter cease to be effective or fail to be usable for its intended purpose without being succeeded within a reasonable period of time by a post-effective amendment to the Registration Statement, a supplement to the prospectus or a report filed with the Commission pursuant to Section 13(a), 13(c), 14 or l5(d) of the Exchange Act, then, until the suspension is lifted or a post-effective amendment, supplement or report is filed with the Commission and effective, but not including any day on which a suspension is lifted or such amendment, supplement or report is filed and effective, if applicable, Atlas shall owe the Holders an amount equal to the Liquidated Damages, following (x) the date on which the suspension period exceeded the permitted period under Section 2.01(b) of this Agreement or (y) the date after the Registration Statement ceased to be effective or failed to be useable for its intended purposes, as liquidated damages and not as a penalty. For purposes of this Section 2.01(c), a suspension shall be deemed lifted on the date that notice that the suspension has been lifted or that a post-effective amendment is effective is delivered to the Holders pursuant to Section 3.01 of this Agreement.

Section 2.02 Piggyback Rights.

(a) Participation. If at any time Atlas proposes to file (i) a shelf registration statement other than the Registration Statement (in which event Atlas covenants and agrees to include thereon a description of the transaction under which the Purchasers acquired the Registrable Securities), (ii) a prospectus supplement to an effective shelf registration statement, other than the Registration Statement contemplated by Section 2.01 of this Agreement and Holders may be included without the filing of a post-effective amendment thereto, or (iii) a registration statement, other than a shelf registration statement, in either case, for the sale of Common Units in an Underwritten Offering for its own account and/or another Person, then as soon as practicable but not less than three Business Days prior to the filing of (x) any preliminary prospectus supplement relating to such Underwritten Offering pursuant to Rule 424(b) under the Securities Act, (y) the prospectus supplement relating to such Underwritten Offering pursuant to Rule 424(b) under the Securities Act (if no preliminary prospectus supplement is used) or (z) such registration statement, as the case may be, then Atlas shall give notice (including, but not limited to, notification by electronic mail) of such proposed Underwritten Offering to the Holders and such notice shall offer the Holders the opportunity to include in such Underwritten Offering such number of Common Units (the “Included Registrable Securities”) as each such Holder may request in writing; provided, however, that if Atlas has been advised by the Managing Underwriter that the inclusion of Registrable Securities for sale for the benefit of the Holders will have a material adverse effect on the price, timing or distribution of the Common Units in the Underwritten Offering, then the amount of Registrable Securities to be offered for the accounts of Holders shall be determined based on the provisions of Section 2.02(b) of this Agreement. The notice required to be provided in this Section 2.02(a) to Holders shall be

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provided on a Business Day pursuant to Section 3.01 hereof and receipt of such notice shall be confirmed by such Holder. Each such Holder shall then have three Business Days after receiving such notice to request inclusion of Registrable Securities in the Underwritten Offering. If no request for inclusion from a Holder is received within the specified time, such Holder shall have no further right to participate in such Underwritten Offering. If, at any time after giving written notice of its intention to undertake an Underwritten Offering and prior to the closing of such Underwritten Offering, Atlas shall determine for any reason not to undertake or to delay such Underwritten Offering, Atlas may, at its election, give written notice of such determination to the Selling Holders and, (x) in the case of a determination not to undertake such Underwritten Offering, shall be relieved of its obligation to sell any Included Registrable Securities in connection with such terminated Underwritten Offering, and (y) in the case of a determination to delay such Underwritten Offering, shall be permitted to delay offering any Included Registrable Securities for the same period as the delay in the Underwritten Offering. Any Selling Holder shall have the right to withdraw such Selling Holder’s request for inclusion of such Selling Holder’s Registrable Securities in such offering by giving written notice to Atlas of such withdrawal up to and including the time of pricing of such offering. Each Holder’s rights under this Section 2.02(a) shall terminate when such Holder (together with any Affiliates of such Holder) holds, directly or indirectly, including pursuant to a total return swap or similar transaction, less than $15 million, in aggregate, of Registrable Securities, based on the Common Unit Price. Notwithstanding the foregoing, any Holder may deliver written notice (an “Opt Out Notice”) to Atlas requesting that such Holder not receive notice from Atlas of any proposed Underwritten Offering; provided, that such Holder may later revoke any such notice. Any Holder that owns Registrable Securities indirectly through a total return swap or similar transaction at the time of receipt of notice of a proposed Underwritten Offering pursuant to this Section 2.02(a) shall be eligible to participate in an Underwritten Offering as set forth in this Section 2.02(a); provided, that, to the extent required under the Securities Act or other applicable law to permit such participation, such Holder agrees to unwind such total return swap or similar transaction to the reasonable satisfaction of Atlas in a manner to allow such Holder to sell any Registrable Securities subject to such total return swap or similar transaction in such Underwritten Offering, free and clear of all liens, encumbrances, equities or claims.

(b) Priority of Rights. If the Managing Underwriter or Underwriters of any proposed Underwritten Offering of Common Units included in an Underwritten Offering involving Included Registrable Securities advises Atlas, or Atlas reasonably determines, that the total amount of Registrable Securities that the Selling Holders and any other Persons intend to include in such offering exceeds the number that can be sold in such offering without being likely to have a material adverse effect on the price, timing or distribution of the Common Units offered or the market for the Common Units, then the Registrable Securities to be included in such Underwritten Offering shall include the number of Registrable Securities that such Managing Underwriter or Underwriters advises Atlas, or Atlas reasonably determines, can be sold without having such adverse effect, with such number to be allocated (i) first, to Atlas, and (ii) second, pro rata among the Selling Holders who have requested participation in such Underwritten Offering. The pro rata allocations for each such Selling Holder shall be the product of (a) the aggregate number of Registrable Securities proposed to be sold by all Selling Holders in such Underwritten Offering multiplied by (b) the fraction derived by dividing (x) the number of Registrable Securities owned on the Closing Date by such Selling Holder by (y) the aggregate number of Registrable Securities owned on the Closing Date by all Selling Holders

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participating in the Underwritten Offering. All participating Selling Holders shall have the opportunity to share pro rata that portion of such priority allocable to any Selling Holder(s) not so participating.

Section 2.03 Underwritten Offering.

(a) Request for Underwritten Offering. In the event that one or more Holders collectively holding, directly or indirectly, including pursuant to a total return swap or similar transaction, greater than $40 million of Registrable Securities, based on the Common Unit Price, elect to dispose of Registrable Securities under the Registration Statement pursuant to an Underwritten Offering, Atlas shall retain underwriters, effect such sale though an Underwritten Offering, including entering into an underwriting agreement in customary form with the Managing Underwriter or Underwriters, which shall include, among other provisions, indemnities to the effect and to the extent provided in Section 2.08 and take all reasonable actions as are requested by the Managing Underwriter or Underwriters to expedite or facilitate the disposition of such Registrable Securities. Atlas management shall participate in a roadshow or similar marketing effort on behalf of any such Holder or Holders if gross proceeds from such Underwritten Offering are reasonably expected to exceed $40 million.

(b) Limitation on Underwritten Offerings. In connection with any and all rights granted hereunder to the Holders to cause Atlas to engage underwriters to conduct an Underwritten Offering on behalf of the Holders, in no event shall Atlas be required to do more than aggregate of two such Underwritten Offerings.

(c) General Procedures. In connection with any Underwritten Offering under this Agreement, Atlas shall be entitled to select the Managing Underwriter or Underwriters. In connection with an Underwritten Offering contemplated by this Agreement in which a Selling Holder participates, each Selling Holder and Atlas shall be obligated to enter into an underwriting agreement that contains such representations, covenants, indemnities and other rights and obligations as are customary in underwriting agreements for firm commitment offerings of securities. No Selling Holder may participate in such Underwritten Offering unless such Selling Holder agrees to sell its Registrable Securities on the basis provided in such underwriting agreement and completes and executes all questionnaires, powers of attorney, indemnities and other documents reasonably required under the terms of such underwriting agreement. Each Selling Holder may, at its option, require that any or all of the representations and warranties by, and the other agreements on the part of, Atlas to and for the benefit of such underwriters also be made to and for such Selling Holder’s benefit and that any or all of the conditions precedent to the obligations of such underwriters under such underwriting agreement also be conditions precedent to its obligations. No Selling Holder shall be required to make any representations or warranties to or agreements with Atlas or the underwriters other than representations, warranties or agreements regarding such Selling Holder and its ownership of the securities being registered on its behalf, its intended method of distribution and any other representation required by Law. If any Selling Holder disapproves of the terms of an underwriting, such Selling Holder may elect to withdraw therefrom by notice to Atlas and the Managing Underwriter; provided, however, that such withdrawal must be made at a time up to and including the time of pricing of such Underwritten Offering. No such withdrawal or abandonment shall affect Atlas’s obligation to pay Registration Expenses.

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Section 2.04 Sale Procedures. In connection with its obligations under this Article II, Atlas will, as expeditiously as possible:

(a) prepare and file with the Commission such amendments and supplements to the Registration Statement and the prospectus used in connection therewith as may be necessary to cause the Registration Statement to be effective and to keep the Registration Statement effective for the Effectiveness Period and as may be necessary to comply with the provisions of the Securities Act with respect to the disposition of all securities covered by the Registration Statement;

(b) furnish to each Selling Holder (i) as far in advance as reasonably practicable before filing the Registration Statement or any other registration statement contemplated by this Agreement or any supplement or amendment thereto, upon request, copies of reasonably complete drafts of all such documents proposed to be filed (including exhibits and each document incorporated by reference therein to the extent then required by the rules and regulations of the Commission), and provide each such Selling Holder the opportunity to object to any information pertaining to such Selling Holder and its plan of distribution that is contained therein and make the corrections reasonably requested by such Selling Holder with respect to such information prior to filing the Registration Statement or such other registration statement or supplement or amendment thereto, and (ii) such number of copies of the Registration Statement or such other registration statement and the prospectus included therein and any supplements and amendments thereto as such Persons may reasonably request in order to facilitate the public sale or other disposition of the Registrable Securities covered by such Registration Statement or other registration statement;

(c) if applicable, use its commercially reasonable efforts to register or qualify the Registrable Securities covered by the Registration Statement or any other registration statement contemplated by this Agreement under the securities or blue sky laws of such jurisdictions as the Selling Holders or, in the case of an Underwritten Offering, the Managing Underwriter, shall reasonably request; provided, however, that Atlas will not be required to qualify generally to transact business in any jurisdiction where it is not then required to so qualify or to take any action which would subject it to general service of process in any such jurisdiction where it is not then so subject;

(d) promptly notify each Selling Holder and each underwriter of Registrable Securities, at any time when a prospectus relating thereto is required to be delivered by any of them under the Securities Act, of (i) the filing of the Registration Statement or any other registration statement contemplated by this Agreement or any prospectus to be used in connection therewith, or any amendment or supplement thereto, and, with respect to such Registration Statement or any other registration statement or any post-effective amendment thereto, when the same has become effective; and (ii) any written comments from the Commission with respect to any filing referred to in clause (i) and any written request by the Commission for amendments or supplements to the Registration Statement or any other registration statement or any prospectus or prospectus supplement thereto;

(e) immediately notify each Selling Holder and each underwriter of Registrable Securities, at any time when a prospectus relating thereto is required to be delivered

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under the Securities Act, of (i) the happening of any event as a result of which the prospectus or prospectus supplement contained in the Registration Statement or any other registration statement contemplated by this Agreement, as then in effect, includes an untrue statement of a material fact or omits to state any material fact required to be stated therein or necessary to make the statements therein not misleading in the light of the circumstances then existing; (ii) the issuance or threat of issuance by the Commission of any stop order suspending the effectiveness of the Registration Statement or any other registration statement contemplated by this Agreement, or the initiation of any proceedings for that purpose; or (iii) the receipt by Atlas of any notification with respect to the suspension of the qualification of any Registrable Securities for sale under the applicable securities or blue sky laws of any jurisdiction. Following the provision of such notice, Atlas agrees to as promptly as practicable amend or supplement the prospectus or prospectus supplement or take other appropriate action so that the prospectus or prospectus supplement does not include an untrue statement of a material fact or omit to state a material fact required to be stated therein or necessary to make the statements therein not misleading in the light of the circumstances then existing and to take such other action as is necessary to remove a stop order, suspension, threat thereof or proceedings related thereto;

(f) upon request and subject to appropriate confidentiality obligations, furnish to each Selling Holder copies of any and all transmittal letters or other correspondence with the Commission or any other governmental agency or self-regulatory body or other body having jurisdiction (including any domestic or foreign securities exchange) relating to such offering of Registrable Securities;

(g) in the case of an Underwritten Offering, furnish upon request, (i) an opinion of counsel for Atlas dated the effective date of the applicable registration statement or the date of any amendment or supplement thereto, and a letter of like kind dated the date of the closing under the underwriting agreement, and (ii) a “cold comfort” letter, dated the date of the applicable registration statement or the date of any amendment or supplement thereto and a letter of like kind dated the date of the closing under the underwriting agreement, in each case, signed by the independent public accountants who have certified Atlas’s financial statements included or incorporated by reference into the applicable registration statement, and each of the opinion and the “cold comfort” letter shall be in customary form and covering substantially the same matters with respect to such registration statement (and the prospectus and any prospectus supplement included therein) as are customarily covered in opinions of issuer’s counsel and in accountants’ letters delivered to the underwriters in Underwritten Offerings of securities and such other matters as such underwriters or Selling Holders may reasonably request;

(h) otherwise use its commercially reasonable efforts to comply with all applicable rules and regulations of the Commission, and make available to its security holders, as soon as reasonably practicable, an earnings statement, which earnings statement shall satisfy the provisions of Section 11(a) of the Securities Act and Rule 158 promulgated thereunder;

(i) make available to the appropriate representatives of the Managing Underwriter and Selling Holders access to such information and Atlas personnel as is reasonable and customary to enable such parties to establish a due diligence defense under the Securities Act; provided, however, that Atlas need not disclose any such information to any such representative unless and until such representative has entered into or is otherwise subject to a

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confidentiality agreement with Atlas satisfactory to Atlas (including any confidentiality agreement referenced in Section 8.06 of the Purchase Agreement);

(j) cause all such Registrable Securities registered pursuant to this Agreement to be listed on each securities exchange or nationally recognized quotation system on which similar securities issued by Atlas are then listed;

(k) use its commercially reasonable efforts to cause the Registrable Securities to be registered with or approved by such other governmental agencies or authorities as may be necessary by virtue of the business and operations of Atlas to enable the Selling Holders to consummate the disposition of such Registrable Securities;

(l) provide a transfer agent and registrar for all Registrable Securities covered by such registration statement not later than the effective date of such registration statement;

(m) enter into customary agreements and take such other actions as are reasonably requested by the Selling Holders or the underwriters, if any, in order to expedite or facilitate the disposition of such Registrable Securities;

(n) If any Purchaser could reasonably be deemed to be an “underwriter,” as defined in Section 2(a)(11) of the Securities Act, in connection with the registration statement in respect of any registration of Registrable Securities of such Purchaser pursuant to this Agreement, and any amendment or supplement thereof (any such registration statement or amendment or supplement, a “Purchaser Underwriter Registration Statement”), then for a period of one year following the File Date, Atlas will cooperate with such Purchaser in allowing such Purchaser to conduct customary “underwriter’s due diligence” with respect to Atlas and satisfy its obligations in respect thereof. In addition, for a period of one year following the File Date at any Purchaser’s request, Atlas will furnish to such Purchaser, on the date of the effectiveness of any Purchaser Underwriter Registration Statement and thereafter no more often than on a quarterly basis, (i) a letter, dated such date, from Atlas’s independent certified public accountants in form and substance as is customarily given by independent certified public accountants to underwriters in an underwritten public offering, addressed to such Purchaser, (ii) an opinion, dated as of such date, of counsel representing Atlas for purposes of such Purchaser Underwriter Registration Statement, in form, scope and substance as is customarily given in an underwritten public offering, including a standard “10b-5” opinion for such offering, addressed to such Purchaser and (iii) a standard officer’s certificate from the Chief Executive Officer and Chief Financial Officer of Atlas addressed to such Purchaser; provided, however, that with respect to any Placement Agent, Atlas’s obligations with respect to this Section 2.04(n) shall be limited to one time, with an additional bring down request within 30 days of the date of such documents. Atlas will also permit one legal counsel to such Purchaser(s) to review and comment upon any such Purchaser Underwriter Registration Statement at least five Business Days prior to its filing with the Commission and all amendments and supplements to any such Purchaser Underwriter Registration Statement within a reasonable number of days prior to their filing with the Commission and not file any Purchaser Underwriter Registration Statement or amendment or supplement thereto in a form to which such Purchaser’s legal counsel reasonably objects;

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(o) Each Selling Holder, upon receipt of notice from Atlas of the happening of any event of the kind described in Section 2.04(e) of this Agreement, shall forthwith discontinue disposition of the Registrable Securities until such Selling Holder’s receipt of the copies of the supplemented or amended prospectus contemplated by Section 2.04(e) of this Agreement or until it is advised in writing by Atlas that the use of the prospectus may be resumed and has received copies of any additional or supplemental filings incorporated by reference in the prospectus, and, if so directed by Atlas, such Selling Holder will, or will request the managing underwriter or underwriters, if any, to deliver to Atlas (at Atlas’s expense) all copies in their possession or control, other than permanent file copies then in such Selling Holder’s possession, of the prospectus covering such Registrable Securities current at the time of receipt of such notice;

(p) If requested by a Purchaser, Atlas shall: (i) as soon as practicable incorporate in a prospectus supplement or post-effective amendment such information as such Purchaser reasonably requests to be included therein relating to the sale and distribution of Registrable Securities, including information with respect to the number of Registrable Securities being offered or sold, the purchase price being paid therefor and any other terms of the offering of the Registrable Securities to be sold in such offering; (ii) as soon as practicable make all required filings of such prospectus supplement or post-effective amendment after being notified of the matters to be incorporated in such prospectus supplement or post-effective amendment; and (iii) as soon as practicable, supplement or make amendments to any Registration Statement; and

(q) Include in the plan of distribution section of a registrations statement the following language with respect to the selling unitholders:

“The selling unitholders may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by the selling unitholders or borrowed from the selling unitholders or others to settle those sales or to close out any related open borrowings of Units, and may use securities received from the selling unitholders in settlement of those derivatives to close out any related open borrowings of Units.”

Section 2.05    Cooperation by Holders. Atlas shall have no obligation to include in the Registration Statement Registrable Securities of a Holder, or in an Underwritten Offering pursuant to Section 2.02 Registrable Securities of a Selling Holder, who has failed to timely furnish such information that Atlas determines, after consultation with counsel, is reasonably required to be furnished or conformed in order for the registration statement or prospectus supplement, as applicable, to comply with the Securities Act.

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Section 2.06 Restrictions on Public Sale by Holders of Registrable Securities. For a period of 365 days from the Closing Date, each Holder of Registrable Securities agrees not to effect any public sale or distribution of the Registrable Securities for a period of up to 30 days following completion of an Underwritten Offering of equity securities by Atlas (except as provided in this Section 2.06); provided, however, that the duration of the foregoing restrictions shall be no longer than the duration of the shortest restriction generally imposed by the underwriters on the officers or directors or any other Unitholder of Atlas on whom a restriction is imposed in connection with such public offering.

Section 2.07 Expenses.

(a) Certain Definitions. “Registration Expenses” means all expenses incident to Atlas’s performance under or compliance with this Agreement to effect the registration of Registrable Securities on the Registration Statement pursuant to Section 2.01 hereof or an Underwritten Offering covered under this Agreement, and the disposition of such securities, including, without limitation, all registration, filing, securities exchange listing and The New York Stock Exchange fees, all registration, filing, qualification and other fees and expenses of complying with securities or blue sky laws, fees of the National Association of Securities Dealers, Inc., transfer taxes and fees of transfer agents and registrars, all word processing, duplicating and printing expenses and the fees and disbursements of one counsel to the Holders and independent public accountants for Atlas, including the expenses of any special audits or “cold comfort” letters required by or incident to such performance and compliance. “Selling Expenses” means all underwriting fees, discounts and selling commissions allocable to the sale of the Registrable Securities.

(b) Expenses. Atlas will pay all reasonable Registration Expenses as determined in good faith, including, in the case of an Underwritten Offering, whether or not any sale is made pursuant to such Underwritten Offering. In addition, except as otherwise provided in Section 2.08 hereof, Atlas shall not be responsible for legal fees incurred by Holders in connection with the exercise of such Holders’ rights hereunder. Each Selling Holder shall pay its pro rata share of all Selling Expenses in connection with any sale of its Registrable Securities hereunder.

Section 2.08 Indemnification.

(a) By Atlas. In the event of an offering of any Registrable Securities under the Securities Act pursuant to this Agreement, Atlas will indemnify and hold harmless each Selling Holder thereunder, its Affiliates that own Registrable Securities and their respective directors and officers, and each underwriter, pursuant to the applicable underwriting agreement with such underwriter, of Registrable Securities thereunder and each Person, if any, who controls such Selling Holder or underwriter within the meaning of the Securities Act and the Exchange Act, and its directors and officers (collectively, the “Selling Holder Indemnified Persons”), against any losses, claims, damages, expenses or liabilities (including reasonable attorneys’ fees and expenses) (collectively, “Losses”), joint or several, to which such Selling Holder Indemnified Person may become subject under the Securities Act, the Exchange Act or otherwise, insofar as such Losses (or actions or proceedings, whether commenced or threatened, in respect thereof) arise out of or are based upon any untrue statement or alleged untrue

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statement of any material fact contained in the Registration Statement or any other registration statement contemplated by this Agreement, any preliminary prospectus, free writing prospectus or final prospectus contained therein, or any amendment or supplement thereof, arise out of or are based upon the omission or alleged omission to state therein a material fact required to be stated therein or necessary to make the statements therein (in the case of a prospectus, in light of the circumstances under which they were made) not misleading or arise out of or are based upon a Selling Holder being deemed to be an “underwriter,” as defined in Section 2(a)(11) of the Securities Act, in connection with the registration statement in respect of any registration of Atlas’s securities, and will reimburse each such Selling Holder Indemnified Person for any legal or other expenses reasonably incurred by them in connection with investigating or defending any such Loss or actions or proceedings; provided, however, that Atlas will not be liable in any such case if and to the extent that any such Loss arises out of or is based upon an untrue statement or alleged untrue statement or omission or alleged omission so made in strict conformity with information furnished by such Selling Holder Indemnified Person in writing specifically for use in the Registration Statement or such other registration statement, or prospectus supplement, as applicable. Such indemnity shall remain in full force and effect regardless of any investigation made by or on behalf of such Selling Holder or any such Selling Holder, its directors or officers or any underwriter or controlling Person, and shall survive the transfer of such securities by such Selling Holder.

(b) By Each Selling Holder. Each Selling Holder agrees severally and not jointly to indemnify and hold harmless Atlas, its directors and officers, and each Person, if any, who controls Atlas within the meaning of the Securities Act or of the Exchange Act, and its directors and officers, to the same extent as the foregoing indemnity from Atlas to the Selling Holders, but only with respect to information regarding such Selling Holder furnished in writing by or on behalf of such Selling Holder expressly for inclusion in the Registration Statement or any preliminary prospectus or final prospectus included therein, or any amendment or supplement thereto; provided, however, that the liability of each Selling Holder shall not be greater in amount than the dollar amount of the proceeds (net of any Selling Expenses) received by such Selling Holder from the sale of the Registrable Securities giving rise to such indemnification.

(c) Notice. Promptly after receipt by an indemnified party hereunder of notice of the commencement of any action, such indemnified party shall, if a claim in respect thereof is to be made against the indemnifying party hereunder, notify the indemnifying party in writing thereof, but the omission so to notify the indemnifying party shall not relieve it from any liability which it may have to any indemnified party other than under this Section 2.08. In any action brought against any indemnified party, it shall notify the indemnifying party of the commencement thereof. The indemnifying party shall be entitled to participate in and, to the extent it shall wish, to assume and undertake the defense thereof with counsel reasonably satisfactory to such indemnified party and, after notice from the indemnifying party to such indemnified party of its election so to assume and undertake the defense thereof, the indemnifying party shall not be liable to such indemnified party under this Section 2.08 for any legal expenses subsequently incurred by such indemnified party in connection with the defense thereof other than reasonable costs of investigation and of liaison with counsel so selected; provided, however, that, (i) if the indemnifying party has failed to assume the defense or employ counsel reasonably acceptable to the indemnified party or (ii) if the defendants in any such action

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include both the indemnified party and the indemnifying party and counsel to the indemnified party shall have concluded that there may be reasonable defenses available to the indemnified party that are different from or additional to those available to the indemnifying party, or if the interests of the indemnified party reasonably may be deemed to conflict with the interests of the indemnifying party, then the indemnified party shall have the right to select a separate counsel and to assume such legal defense and otherwise to participate in the defense of such action, with the reasonable expenses and fees of such separate counsel and other reasonable expenses related to such participation to be reimbursed by the indemnifying party as incurred. Notwithstanding any other provision of this Agreement, no indemnified party shall settle any action brought against it with respect to which it is entitled to indemnification hereunder without the consent of the indemnifying party, unless the settlement thereof imposes no liability or obligation on, and includes a complete and unconditional release from all liability of, the indemnifying party.

(d) Contribution. If the indemnification provided for in this Section 2.08 is held by a court or government agency of competent jurisdiction to be unavailable to any indemnified party or is insufficient to hold them harmless in respect of any Losses, then each such 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 Loss in such proportion as is appropriate to reflect the relative fault of the indemnifying party on the one hand and of such indemnified party on the other in connection with the statements or omissions which resulted in such Losses, as well as any other relevant equitable considerations; provided, however, that in no event shall such Selling Holder be required to contribute an aggregate amount in excess of the dollar amount of proceeds (net of Selling Expenses) received by such Selling Holder from the sale of Registrable Securities giving rise to such indemnification. The relative fault of the indemnifying party on the one hand and the indemnified party on the other shall be determined by reference to, among other things, whether the untrue or alleged untrue statement of a material fact or the omission or alleged omission to state a material fact has been made by, or relates to, information supplied by such party, and the parties’ relative intent, knowledge, access to information and opportunity to correct or prevent such statement or omission. The parties hereto agree that it would not be just and equitable if contributions pursuant to this paragraph were to be determined by pro rata allocation or by any other method of allocation which does not take account of the equitable considerations referred to herein. The amount paid by an indemnified party as a result of the Losses referred to in the first sentence of this paragraph shall be deemed to include any legal and other expenses reasonably incurred by such indemnified party in connection with investigating or defending any Loss which is the subject of this paragraph. 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 is not guilty of such fraudulent misrepresentation.

(e) Other Indemnification. The provisions of this Section 2.08 shall be in addition to any other rights to indemnification or contribution which an indemnified party may have pursuant to law, equity, contract or otherwise.

Section 2.09 Rule 144 Reporting. With a view to making available the benefits of certain rules and regulations of the Commission that may permit the sale of the Registrable Securities to the public without registration, Atlas agrees to use its commercially reasonable efforts to:

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(a) make and keep public information regarding Atlas available, as those terms are understood and defined in Rule 144 under the Securities Act, at all times from and after the date hereof;

(b) file with the Commission in a timely manner all reports and other documents required of Atlas under the Securities Act and the Exchange Act at all times from and after the date hereof; and

(c) so long as a Holder owns any Registrable Securities, furnish, unless otherwise available at no charge by access electronically to the Commission’s EDGAR filing system, to such Holder forthwith upon request a copy of the most recent annual or quarterly report of Atlas, and such other reports and documents so filed as such Holder may reasonably request in availing itself of any rule or regulation of the Commission allowing such Holder to sell any such securities without registration.

Section 2.10 Transfer or Assignment of Registration Rights. The rights to cause Atlas to register Registrable Securities granted to the Purchasers by Atlas under this Article II may be transferred or assigned by any Purchaser to one or more transferee(s) or assignee(s) of such Registrable Securities or by total return swap or similar transaction; provided, however, that, except with respect to a total return swap or similar transaction, for any such assignment to be effective, (a) such transferee or assignee must be an Affiliate of such Purchaser or another Purchaser, (b) Atlas must be given written notice prior to any said transfer or assignment, stating the name and address of each such transferee or assignee and identifying the securities with respect to which such registration rights are being transferred or assigned, and (c) such transferee or assignee must assume in writing responsibility for its portion of the obligations of such Purchaser under this Agreement.

Section 2.11 Limitation on Subsequent Registration Rights. From and after the date hereof, Atlas shall not, without the prior written consent of the Holders of a majority of the outstanding Registrable Securities, (i) enter into any agreement with any current or future holder of any securities of Atlas that would allow such current or future holder to require Atlas to include securities in any registration statement filed by Atlas on a basis that is superior in any way to the piggyback rights granted to the Purchasers hereunder or (ii) grant registration rights to any other Person that would be superior to the Purchasers’ registration rights hereunder.

ARTICLE III

MISCELLANEOUS

Section 3.01 Communications. All notices and other communications provided for or permitted hereunder shall be made in writing by facsimile, electronic mail, courier service or personal delivery:

(a) if to Atlas, to the address set forth on its signature page;

(b) if to a Purchaser, to the address set forth on Exhibit A; and

(c) if to a transferee of Purchaser, to such Holder at the address provided pursuant to Section 2.10 hereof.

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All such notices and communications shall be deemed to have been received: at the time delivered by hand, if personally delivered; when receipt acknowledged, if sent via facsimile or electronic mail; and when actually received, if sent by courier service or any other means.

Section 3.02 Successor and Assigns. This Agreement shall inure to the benefit of and be binding upon the successors and assigns of each of the parties, including subsequent Holders of Registrable Securities to the extent permitted herein.

Section 3.03 Aggregation of Purchased Units. All Purchased Units held or acquired by Persons who are Affiliates of one another shall be aggregated together for the purpose of determining the availability of any rights under this Agreement.

Section 3.04 Recapitalization, Exchanges, Etc. Affecting the Units. The provisions of this Agreement shall apply to the full extent set forth herein with respect to any and all units of Atlas or any successor or assign of Atlas (whether by merger, consolidation, sale of assets or otherwise) which may be issued in respect of, in exchange for or in substitution of, the Registrable Securities, and shall be appropriately adjusted for combinations, unit splits, recapitalizations and the like occurring after the date of this Agreement.

Section 3.05 Change of Control. Atlas shall not merge, consolidate or combine with any other Person unless the agreement providing for such merger, consolidation or combination expressly provides for the continuation of the registration rights specified in this Agreement with respect to the Registrable Securities or other equity securities issued pursuant to such merger, consolidation or combination.

Section 3.06 Specific Performance. Damages in the event of breach of this Agreement by a party hereto may be difficult, if not impossible, to ascertain, and it is therefore agreed that each such Person, in addition to and without limiting any other remedy or right it may have, will have the right to an injunction or other equitable relief in any court of competent jurisdiction, enjoining any such breach, and enforcing specifically the terms and provisions hereof, and each of the parties hereto hereby waives any and all defenses it may have on the ground of lack of jurisdiction or competence of the court to grant such an injunction or other equitable relief. The existence of this right will not preclude any such Person from pursuing any other rights and remedies at law or in equity which such Person may have.

Section 3.07 Counterparts. This Agreement may be executed in any number of counterparts and by different parties hereto in separate counterparts, each of which counterparts, when so executed and delivered, shall be deemed to be an original and all of which counterparts, taken together, shall constitute but one and the same Agreement.

Section 3.08 Headings. The headings in this Agreement are for convenience of reference only and shall not limit or otherwise affect the meaning hereof.

Section 3.09 Governing Law. The Laws of the State of New York shall govern this Agreement without regard to principles of conflict of Laws.

Section 3.10 Severability of Provisions. Any provision of this Agreement which is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the

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extent of such prohibition or unenforceability without invalidating the remaining provisions hereof or affecting or impairing the validity or enforceability of such provision in any other jurisdiction.

Section 3.11 Entire Agreement. This Agreement is intended by the parties as a final expression of their agreement and intended to be a complete and exclusive statement of the agreement and understanding of the parties hereto in respect of the 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 rights granted by Atlas set forth herein. This Agreement and the Purchase Agreement supersede all prior agreements and understandings between the parties with respect to such subject matter.

Section 3.12 Amendment. This Agreement may be amended only by means of a written amendment signed by Atlas and the Holders of a majority of the then outstanding Registrable Securities; provided, however, that no such amendment shall materially and adversely affect the rights of any Holder hereunder without the consent of such Holder.

Section 3.13 No Presumption. If any claim is made by a party relating to any conflict, omission or ambiguity in this Agreement, no presumption or burden of proof or persuasion shall be implied by virtue of the fact that this Agreement was prepared by or at the request of a particular party or its counsel.

Section 3.14 Obligations Limited to Parties to Agreement. Each of the Parties hereto covenants, agrees and acknowledges that no Person other than the Purchasers (and their permitted assignees) and Atlas shall have any obligation hereunder and that, notwithstanding that one or more of the Purchasers may be a corporation, partnership or limited liability company, no recourse under this Agreement or the Purchase Agreement or under any documents or instruments delivered in connection herewith or therewith shall be had against any former, current or future director, officer, employee, agent, general or limited partner, manager, member, stockholder or Affiliate of any of the Purchasers or any former, current or future director, officer, employee, agent, general or limited partner, manager, member, stockholder or Affiliate of any of the foregoing, whether by the enforcement of any assessment or by any legal or equitable proceeding, or by virtue of any applicable Law, it being expressly agreed and acknowledged that no personal liability whatsoever shall attach to, be imposed on or otherwise be incurred by any former, current or future director, officer, employee, agent, general or limited partner, manager, member, stockholder or Affiliate of any of the Purchasers or any former, current or future director, officer, employee, agent, general or limited partner, manager, member, stockholder or Affiliate of any of the foregoing, as such, for any obligations of the Purchasers under this Agreement or the Purchase Agreement or any documents or instruments delivered in connection herewith or therewith or for any claim based on, in respect of or by reason of such obligation or its creation.

[The remainder of this page is intentionally left blank]

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IN WITNESS WHEREOF, the Parties hereto execute this Agreement, effective as of the date first above written.

	ATLAS RESOURCE PARTNERS, L.P.
	By: Atlas Resource Partners GP, LLC, its general partner
	By:	/s/ Sean P. McGrath
		Name: Sean P. McGrath
		Title: Chief Financial Officer
Address for notices:	Atlas Resource Partners, L.P. 1000 Commerce Dr., Suite 400
	Pittsburg, PA 15275
	Fax:	412-262-2820
	Attn:	Sean P. McGrath
With copies to:	Ledgewood
	1900 Market Street, Suite 750
	Philadelphia, PA 19103
	Fax:	215-735-2513
	Attn:	Lisa A. Ernst

IN WITNESS WHEREOF, the Parties hereto execute this Agreement, effective as of the date first above written.

Citigroup Global Markets Inc.
By:	/s/ Kevin G. Russell
Name:	Kevin G. Russell
Title:	MD

Cobalt Management, LLC
By:	/s/ Wayne Cooperman
Name:	Wayne Cooperman
Title:	Managing Member

Credit Suisse Mgt LLC
By:	/s/ Gerard Murtagh
Name:	Gerard Murtagh
Title:	MD, Prime Services

/s/ Jonathan Z. Cohen

/s/ Julia Pershan

/s/ Edward E. Cohen

/s/ Betsy Z. Cohen

Arete Foundation
By:	/s/ Edward Cohen
Name:	Edward Cohen
Title:	Trustee

Locustwood Capital, LP
By:	/s/ Stephen J. Errico
Name:	Stephen J. Errico
Title:	Managing Partner

MSD Energy Partners, L.P.
By:	/s/ Marcello Liguori
Name:	Marcello Liguori
Title:	Managing Director of the Investment Manager

Omega Advisors, Inc.*
By:	/s/ Denis Wong
Name:	Denis Wong
Title:	COO

* Not in its individual corporate capacity but in its capacity as the investment manager for the following entities:

Omega Capital Partners, L.P.

Omega Capital Investors, L.P.

Omega Equity Investors, L.P.

Beta Equities, Inc.

GS&Co. Profit Sharing Master Trust

VMT II, LLC

Omega Advisors U.S. Capital Appreciation Fund

The Ministers and Missionaries Benefit Fund of American Baptist Churches

The Royal Bank of Scotland plc

By: RBS Securities Inc., its agent

By: /s/ William Donzeiser

Name: William Donzeiser

Title: Managing Director

In connection with this Agreement, RBS Securities Inc. has acted as agent on behalf of The Royal Bank of Scotland plc. RBS Securities Inc. has not guaranteed and is not otherwise responsible for the obligations of The Royal Bank of Scotland plc, if any, under this Agreement

Senator Global Opportunity Fund LP
By:	/s/ Evan Gartenlaub
Name:	Evan Gartenlaub
Title:	General Counsel

EX-10.1

Exhibit 10.1

FIRST AMENDMENT TO

AMENDED AND RESTATED CREDIT AGREEMENT

dated as of

April 30, 2012

among

ATLAS RESOURCE PARTNERS, L.P.,

as Borrower,

THE LENDERS PARTY HERETO,

and

WELLS FARGO BANK, NATIONAL ASSOCIATION,

as Administrative Agent

WELLS FARGO SECURITIES, LLC,

as Joint Lead Arranger and Joint Bookrunner

CITIBANK, N.A.,

as Joint Lead Arranger, Joint Bookrunner and Syndication Agent

JPMORGAN CHASE BANK, N.A.,

DEUTSCHE BANK SECURITIES INC., and

BANK OF AMERICA, N.A.,

as Co-Documentation Agents

FIRST AMENDMENT TO

AMENDED AND RESTATED CREDIT AGREEMENT

This FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT (this “First Amendment”), dated as of April 30, 2012 (the “First Amendment Effective Date”), is among ATLAS RESOURCE PARTNERS, L.P., a limited partnership formed under the laws of the State of Delaware (the “Borrower”); each of the undersigned guarantors (the “Guarantors”, and together with the Borrower, the “Loan Parties”); each of the Lenders that is a signatory hereto; and WELLS FARGO BANK, NATIONAL ASSOCIATION, as administrative agent for the Lenders (in such capacity, together with its successors, the “Administrative Agent”).

Recitals

A. The Borrower, the Administrative Agent and the Lenders are parties to that certain Amended and Restated Credit Agreement dated as of March 5, 2012 (as amended prior to the date hereof, the “Credit Agreement”), pursuant to which the Lenders have, subject to the terms and conditions set forth therein, made certain credit available to and on behalf of the Borrower.

B. The Borrower has advised the Administrative Agent and the Lenders that ARP Barnett, LLC, a Delaware limited liability company and a Wholly-Owned Subsidiary of the Borrower (the “ARP Barnett”), has entered into that certain Purchase and Sale Agreement dated as of March 15, 2012 (the “Barnett Acquisition Agreement”) among ARP Barnett, the Borrower and Carrizo Oil & Gas, Inc., CLLR, Inc., Hondo Pipeline, Inc. and Mescalero Pipeline, LLC pursuant to which ARP Barnett will acquire certain Oil and Gas Properties located in the oil and gas field commonly known as the “Barnett Shale” and certain other Property as more particularly described in the Barnett Acquisition Agreement (all such Properties, collectively, the “Barnett Assets” and such acquisition, the “Barnett Acquisition”).

C. The Borrower has requested that Sovereign Bank, N.A. (the “New Lender”) become a Lender hereunder with a Maximum Credit Amount in the amount as shown on Annex I to the Credit Agreement (as amended hereby);

D. In connection with the Barnett Acquisition, the parties hereto desire to (i) amend certain terms of the Credit Agreement in certain respects including, without limitation, increasing the Aggregate Maximum Credit Amounts to $500,000,000, and (ii) establish a Borrowing Base of $250,000,000, in each case to be effective as of the First Amendment Effective Date.

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

Section 1. Defined Terms. Each capitalized term which is defined in the Credit Agreement, but which is not defined in this First Amendment, shall have the meaning ascribed such term in the Credit Agreement, as amended hereby. Unless otherwise indicated, all section references in this First Amendment refer to the Credit Agreement.

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Section 2. Amendments. In reliance on the representations, warranties, covenants and agreements contained in this First Amendment, and subject to the satisfaction of the conditions precedent set forth in Section 4 hereof, the Credit Agreement shall be amended effective as of the First Amendment Effective Date in the manner provided in this Section 2.

2.1 Additional Definitions. Section 1.02 of the Credit Agreement is hereby amended to add thereto in alphabetical order the following definition which shall read in full as follows:

“ARP Barnett” means ARP Barnett, LLC, a Delaware limited liability company.

“Barnett Acquisition Agreement” has the meaning given to such term in the First Amendment.

“Barnett Assets” has the meaning given to such term in the First Amendment.

“First Amendment” means that certain First Amendment to Amended and Restated Credit Agreement dated as of April 30, 2012, among the Borrower, the Guarantors, the Administrative Agent and the Lenders.

“First Amendment Effective Date” means April 30, 2012.

2.2 Amended Definitions. The definitions of “Applicable Margin”, “Borrowing Base”, “Commitment”, “Loan Documents”, “Maximum Credit Amount”, and “Swap Agreement” contained in Section 1.02 of the Credit Agreement are hereby amended and restated in their entirety to read in full as follows:

“Applicable Margin” means, for any day, with respect to any Loan, the applicable rate per annum set forth below based on Borrowing Base Utilization Percentage on such day:

Borrowing Base Utilization Percentage	Eurodollar Loans			ABR Loans
³ 90%		3.00	%		2.00	%
³ 75% and < 90%		2.75	%		1.75	%
³ 50% and < 75%		2.25	%		1.25	%
< 50%		2.00	%		1.00	%

Each change in the Applicable Margin shall apply during the period commencing on the effective date of a change in the Borrowing Base Utilization Percentage and ending on the date immediately preceding the effective date of the next such change.

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“Borrowing Base” means at any time an amount equal to the sum of the Oil and Gas Reserve Borrowing Base plus the Well Services Borrowing Base determined in accordance with Section 2.07, as the same may be adjusted from time to time between Redetermination Dates pursuant to Section 2.07(f), Section 2.07(h), or Section 8.12(d). As of the First Amendment Effective Date, the Borrowing Base shall be $250,000,000.

“Commitment” means, with respect to each Lender, the commitment of such Lender to make Loans and to acquire participations in Letters of Credit hereunder, expressed as an amount representing the maximum aggregate amount of such Lender’s Credit Exposure hereunder, as such commitment may be (a) modified from time to time pursuant to Section 2.06 and (b) modified from time to time pursuant to assignments by or to such Lender pursuant to Section 12.04(b); and “Commitments” means the aggregate amount of the Commitments of all the Lenders. The amount representing each Lender’s Commitment shall at any time be the lesser of (i) such Lender’s Maximum Credit Amount and (ii) such Lender’s Applicable Percentage of the then effective Borrowing Base. As of the First Amendment Effective Date, the aggregate Commitments of the Lenders are $250,000,000.

“Loan Documents” means this Agreement, the First Amendment, the Notes, if any, the Letter of Credit Agreements, the Letters of Credit, the Security Instruments, the Intercreditor Agreement and any and all other material agreements or instruments now or hereafter executed and delivered by any Loan Party or any other Person (other than Swap Agreements or agreements regarding the provision of Bank Products with the Lenders or any Affiliate of a Lender or participation or similar agreements between any Lender and any other lender or creditor with respect to any Indebtedness pursuant to this Agreement) in connection with the Indebtedness, this Agreement and the transactions contemplated hereby, as such agreements may be amended, modified, supplemented or restated from time to time.

“Maximum Credit Amount” means, as to each Lender, the amount set forth opposite such Lender’s name on Annex I under the caption “Maximum Credit Amounts”, as the same may be (a) reduced or terminated from time to time in connection with a reduction or termination of the Aggregate Maximum Credit Amounts pursuant to Section 2.06(b) or (b) modified from time to time pursuant to any assignment permitted by Section 12.04(b). As of the First Amendment Effective Date, the aggregate Maximum Credit Amounts of the Lenders are $500,000,000.

“Swap Agreement” means any agreement with respect to any swap, forward, future or derivative transaction or option or similar agreement, whether exchange traded, “over-the-counter” or otherwise, involving, or settled by reference to, one or more rates, currencies, commodities, equity or debt instruments or securities, or economic, financial or pricing indices or measures of economic, financial or pricing risk or value or any similar transaction or any

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combination of these transactions. For the sole purposes of Section 9.17, the term “Swap Agreement” shall be deemed to exclude all purchased put options or floors for Hydrocarbons.

2.3 New Swap Agreements Affirmative Covenant. A new Section 8.20 is hereby added to the Credit Agreement and shall read in full as follows:

Section 8.20 Swap Agreements for Barnett Production. On or before the thirtieth (30th) day following the First Amendment Effective Date, the Borrower shall, or shall cause ARP Barnett or another Loan Party to, enter into incremental Swap Agreements following the First Amendment Closing Date reasonably satisfactory to the Administrative Agent with respect to production from the Barnett Assets to hedge notional volumes not less than (a) 50% (for each month during calendar years 2012 and 2013) and (b) 40% (for each month during calendar year 2014) of the reasonably anticipated projected production from proved, developed and producing Oil and Gas Properties comprising the Barnett Assets.

2.4 Amendment to Material Contracts Covenant. Section 9.21 of the Credit Agreement is hereby amended and restated in its entirety to read in full as follows:

Section 9.21 Acquisition Documents, the Separation Agreement and the Contribution Agreement. The Borrower will not, nor will the Borrower permit the Existing Borrower or any Restricted Subsidiary to, directly or indirectly, amend or otherwise modify any Acquisition Document, the Barnett Acquisition Agreement, the Separation Agreement or the Contribution Agreement which in any case (a) violates the terms of this Agreement or any other Loan Document, (b) could reasonably be expected to be materially adverse to the rights, interests or privileges of the Administrative Agent or the Lenders or their ability to enforce the Loan Documents or (c) could reasonably be expected to have a Material Adverse Effect.

2.5 Amendment to Section 10.02(c) of the Credit Agreement. Section 10.02(c) of the Credit Agreement is hereby amended and restated in its entirety to read in full as follows:

(c) All proceeds realized from the liquidation or other disposition of collateral or otherwise received after the Termination Date, whether by acceleration or otherwise, shall be applied: first, to reimbursement of expenses and indemnities provided for in this Agreement and the Security Instruments; second, to accrued interest on the Loans; third, to fees; fourth, pro rata to (i) outstanding principal of the Loans and LC Disbursements, (ii) to serve as cash collateral to be held by the Administrative Agent to secure LC Exposure and (iii) the payment of Indebtedness referred to in clauses (b) and (c) of the definition of Indebtedness; fifth, to any other Indebtedness; and any excess shall be paid to the Borrower or as otherwise required by any Law.

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2.6 Replacement of Annex I. Annex I to the Credit Agreement is hereby replaced in its entirety with Annex I attached hereto and Annex I attached hereto shall be deemed to be attached as Annex I to the Credit Agreement. After giving effect to this First Amendment and any Borrowings made on the First Amendment Effective Date, (a) each Lender who holds Loans in an aggregate amount less than its Applicable Percentage (after giving effect to this First Amendment) of all Loans shall advance new Loans which shall be disbursed to the Administrative Agent and used to repay Loans outstanding to each Lender who holds Loans in an aggregate amount greater than its Applicable Percentage of all Loans, (b) each Lender’s participation in each Letter of Credit, if any, shall be automatically adjusted to equal its Applicable Percentage (after giving effect to this First Amendment), (c) such other adjustments shall be made as the Administrative Agent shall specify so that the Credit Exposure applicable to each Lender equals its Applicable Percentage (after giving effect to this First Amendment) of the aggregate Credit Exposure of all Lenders and (d) the Borrower shall be required to make any break-funding payments required under Section 5.02 of the Credit Agreement resulting from the Loans and adjustments described in this Section 2.6.

Section 3. Borrowing Base. In reliance on the representations, warranties, covenants and agreements contained in this First Amendment, and subject to the satisfaction of the conditions precedent set forth in Section 4 hereof, the Borrowing Base shall be increased, effective as of the First Amendment Effective Date, to be $250,000,000 and shall remain at $250,000,000 until the next Scheduled Redetermination, Interim Redetermination or other adjustment of the Borrowing Base pursuant to the terms of the Credit Agreement. The Borrowing Base redetermination provided for herein shall be the May 1, 2012 Scheduled Redetermination and shall not be considered or deemed to be an Interim Redetermination of the Borrowing Base for purposes of Section 2.07(b) of the Credit Agreement. The Borrowing Base increase provided for herein shall be comprised of the following changes and reaffirmations to the various components of the Borrowing Base: (a) the Working Interest Borrowing Base shall increased from $60,000,000 to $170,000,000; (b) the Partnership Interest Borrowing Base shall be decreased from $60,000,000 to $55,000,000; (c) the Oil and Gas Reserve Borrowing Base shall be increased from $120,000,000 to $225,000,000; and (d) the Well Services Borrowing Base shall be increased from $18,000,000 to $25,000,000.

Section 4. Conditions Precedent. The effectiveness of this First Amendment is subject to the following:

4.1 The Administrative Agent shall have received counterparts of this First Amendment from the Loan Parties and each of the Lenders (including the New Lender).

4.2 The Administrative Agent shall have received all fees and other amounts due and payable on or prior to the effective date of this First Amendment including, without limitation, the Borrowing Base increase fee described in Section 4.3 below.

4.3 Contemporaneously with the effectiveness of the increase of the Borrowing Base contained in Section 3 hereof, the Borrower shall pay to the Administrative Agent, for the benefit of the Lenders, a Borrowing Base increase fee equal to the Increase Fee Percentage (as defined below) on the amount by which the Borrowing Base as established in Section 3 hereof exceeds the Borrowing Base that was in effect immediately prior to the establishment of the new

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Borrowing Base pursuant to Section 3 hereof (the “Increase”). Such fee shall be distributed by Administrative Agent to the Lenders (including the New Lender) in accordance with the portion of the Increase attributable to each such Lender (calculated based on the amount by which (a) an amount equal to such Lender’s Applicable Percentage (as amended hereby) of the Borrowing Base as established in Section 3 hereof exceeds (b) an amount equal to such Lender’s Applicable Percentage of the Borrowing Base (if any) that was in effect immediately prior to the establishment of the new Borrowing Base pursuant to Section 3 hereof). As used herein, the “Increase Fee Percentage” shall be (i) 0.45% for each Lender that delivered to the Administrative Agent prior to the date hereof a commitment to the Borrowing Base established pursuant to Section 3 hereof that was not less than $45,000,000 (regardless of such Lender’s final allocated Commitment as amended hereby) or (ii) 0.40% for each Lender that delivered to the Administrative Agent prior to the date hereof a commitment to the Borrowing Base established pursuant to Section 3 hereof that was less than $45,000,000 (regardless of such Lender’s final allocated Commitment as amended hereby).

4.4 The Administrative Agent shall have received a certificate of the Secretary or an Assistant Secretary of the Borrower and each Guarantor setting forth resolutions of its board of directors (or other applicable managing Person) with respect to the authorization of the Borrower or such Guarantor to execute and deliver this First Amendment and to enter into the transactions contemplated hereby.

4.5 The Administrative Agent shall have received duly executed Notes payable to each Lender requesting a Note in a principal amount equal to its Maximum Credit Amount (as amended hereby) dated as of the date hereof.

4.6 The Administrative Agent shall have received from each party thereto duly executed counterparts (in such number as may be requested by the Administrative Agent) of Mortgages granting the Administrative Agent a Lien over substantially all of the Barnett Assets. In connection with the execution and delivery of such Mortgages, the Administrative Agent shall be reasonably satisfied that the Security Instruments will, when properly executed and recorded, create first priority, perfected Liens (except for Excepted Liens, but subject to the provisos at the end of such definition and subject to Immaterial Title Deficiencies) on at least the Required Mortgage Value of Oil and Gas Properties (including the Barnett Assets).

4.7 The Administrative Agent shall have received an opinion in form and substance reasonably acceptable to the Administrative Agent of (a) Ledgewood, as special counsel to the Loan Parties, and (b) Jones Day, as local counsel in the State of Texas.

4.8 The Administrative Agent shall have received title information in form and substance reasonably satisfactory to the Administrative Agent setting forth the status of title on at least 80% of the total value of all Oil and Gas Properties (including the Barnett Assets, but excluding the Designated Partnership Properties) evaluated in the most recent Reserve Report delivered to the Administrative Agent under the Credit Agreement and, with respect to the Barnett Assets, the January 1, 2012 reserve run report delivered to the Administrative Agent.

4.9 The Administrative Agent shall have received evidence satisfactory to it that all Liens on the Barnett Assets (other than Liens permitted by Section 9.03 of the Credit Agreement)

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associated with any credit facilities and funded debt have been released or terminated, subject only to the filing of applicable terminations and releases.

4.10 The Administrative Agent shall have received a certificate of a Responsible Officer of the Borrower certifying: (a) true, accurate and complete copies of certain of the Barnett Acquisition Agreement and all assignments, bills of sale, side letters and other material agreements, documents and certificates executed and delivered in connection with the Barnett Acquisition, which documents shall contain terms and conditions reasonably acceptable to the Administrative Agent, (b) that, concurrently with the Borrowing under the Credit Agreement on the First Amendment Effective Date, ARP Barnett is (i) consummating the Barnett Acquisition, in accordance with the terms of the Barnett Acquisition Agreement (without waiver or amendment of any term or condition thereof which would be materially adverse to the interests of the Lenders provided that, for the avoidance of doubt, any amendment that removes Oil and Gas Properties from the Barnett Assets or any exercise by ARP Barnett of any right to remove any Oil and Gas Properties from the Barnett Assets shall be deemed to be materially adverse to the interests of the Lenders (other than any exercise by ARP Barnett of its rights to remove Oil and Gas Properties from the Barnett Assets pursuant to Sections 10.2(c)(iii), 10.3(b), 10.4 or 11.1(b)(iii) of the Barnett Acquisition Agreement, which shall not be deemed to be materially adverse to the interests of the Lenders so long as the aggregate “Allocated Values” (as defined in the Barnett Acquisition Agreement) of all such properties removed pursuant to the foregoing Sections does not exceed five percent (5%) of “Purchase Price” as defined in the Barnett Acquisition Agreement without giving effect to any adjustments thereto after March 15, 2012)) and (ii) acquiring all of the Barnett Assets contemplated by the Barnett Acquisition Agreement; (c) as to the final purchase price for the Barnett Assets after giving effect to all adjustments as of the closing date contemplated by the Barnett Acquisition Agreement; (d) that all governmental and third party consents and all equityholder and board of director (or comparable entity management body) authorizations of the Barnett Acquisition required to be obtained by any Loan Party have been obtained and are in full force and effect, (e) that no “Material Adverse Effect” (as defined in the Barnett Acquisition Agreement) shall have occurred and (f) such other related documents and information as the Administrative Agent shall have reasonably requested.

4.11 The Administrative Agent shall have received a certificate of a Responsible Officer of the Borrower certifying that, between the period beginning on March 15, 2012 and ending on or before the First Amendment Effective Date, the Borrower shall have received cash equity proceeds of not less than $80,000,000 from the issuance of its Equity Interests, which certificate shall be accompanied by evidence reasonably satisfactory to the Administrative Agent of such receipt of such cash equity proceeds.

4.12 The Administrative Agent shall be reasonably satisfied with the environmental condition of the Barnett Assets, and shall have received a copy of any environmental site assessments in the possession or control of the Borrower or any Guarantor that was performed within the past three (3) years on any Barnett Asset.

4.13 The conditions set forth in Section 6.02 of the Credit Agreement shall be satisfied; provided that, the only representations and warranties related to the Borrower, ARP Barnett or the Barnett Assets the accuracy of which shall be a condition to the effectiveness of this First Amendment shall be (a) the representations made by the Seller with respect to the Barnett Assets

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in the Barnett Acquisition Agreement that are material to the interests of the Lenders, but only to the extent that ARP Barnett has the right to terminate its obligations under the Barnett Acquisition Agreement (or the right not to consummate the Barnett Acquisition pursuant to the Barnett Acquisition Agreement) as a result of the breach of such representation in the Barnett Acquisition Agreement and (b) the Specified Representations (as defined below). For purposes hereof, “Specified Representations” means, collectively, (i) all representations and warranties of the Loan Parties contained in the Security Instruments relating to the validity, priority and perfection of the Liens created under the Security Instruments and (ii) the representations and warranties of the Borrower set forth in the following sections of the Credit Agreement: Section 7.01, Section 7.02, Section 7.03, Section 7.08, Section 7.09, Section 7.22, Section 7.23 and Section 7.24.

4.14 The Administrative Agent shall have received such other documents as the Administrative Agent or counsel to the Administrative Agent may reasonably request.

Section 5. New Lender. The New Lender hereby joins in, becomes a party to, and agrees to comply with and be bound by the terms and conditions of the Credit Agreement as a Lender thereunder and under each and every other Loan Document to which any Lender is required to be bound by the Credit Agreement, to the same extent as if the New Lender were an original signatory thereto. The New Lender hereby appoints and authorizes the Administrative Agent to take such action as agent on its behalf and to exercise such powers and discretion under the Credit Agreement as are delegated to the Administrative Agent by the terms thereof, together with such powers and discretion as are reasonably incidental thereto. The New Lender represents and warrants that (a) it has full power and authority, and has taken all action necessary, to execute and deliver this First Amendment, to consummate the transactions contemplated hereby and to become a Lender under the Credit Agreement, (b) it has received a copy of the Credit Agreement and copies of the most recent financial statements delivered pursuant to Section 8.01 thereof, and such other documents and information as it has deemed appropriate to make its own credit analysis and decision to enter into this First Amendment and to become a Lender on the basis of which it has made such analysis and decision independently and without reliance on the Administrative Agent or any other Lender, and (c) from and after the First Amendment Effective Date, it shall be a party to and be bound by the provisions of the Credit Agreement and the other Loan Documents and have the rights and obligations of a Lender thereunder.

Section 6. Miscellaneous.

6.1 Confirmation and Effect. The provisions of the Credit Agreement (as amended by this First Amendment) shall remain in full force and effect in accordance with its terms following the effectiveness of this First Amendment. Each reference in the Credit Agreement to “this Agreement”, “hereunder”, “hereof’, “herein”, or words of like import shall mean and be a reference to the Credit Agreement as amended hereby, and each reference to the Credit Agreement in any other document, instrument or agreement executed and/or delivered in connection with the Credit Agreement shall mean and be a reference to the Credit Agreement as amended hereby.

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6.2 Ratification and Affirmation of Loan Parties. Each of the Loan Parties hereby expressly (i) acknowledges the terms of this First Amendment, (ii) ratifies and affirms its obligations under the Guaranty Agreement and the other Loan Documents to which it is a party, (iii) acknowledges, renews and extends its continued liability under the Guaranty Agreement and the other Loan Documents to which it is a party and (iv) agrees that its guarantee under the Guaranty Agreement and the other Loan Documents to which it is a party remains in full force and effect with respect to the Indebtedness as amended hereby.

6.3 Counterparts. This First Amendment may be executed by one or more of the parties hereto in any number of separate counterparts, and all of such counterparts taken together shall be deemed to constitute one and the same instrument. Delivery of this First Amendment by facsimile or electronic (e.g. pdf) transmission shall be effective as delivery of a manually executed original counterpart hereof.

6.4 No Oral Agreement. THIS WRITTEN FIRST AMENDMENT, THE CREDIT AGREEMENT AND THE OTHER LOAN DOCUMENTS EXECUTED IN CONNECTION HEREWITH AND THEREWITH REPRESENT THE FINAL AGREEMENT BETWEEN THE PARTIES AND MAY NOT BE CONTRADICTED BY EVIDENCE OF PRIOR, CONTEMPORANEOUS, OR UNWRITTEN ORAL AGREEMENTS OF THE PARTIES. THERE ARE NO SUBSEQUENT ORAL AGREEMENTS BETWEEN THE PARTIES.

6.5 Governing Law. THIS FIRST AMENDMENT (INCLUDING, BUT NOT LIMITED TO, THE VALIDITY AND ENFORCEABILITY HEREOF) SHALL BE GOVERNED BY, AND CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

6.6 Payment of Expenses. The Borrower agrees to pay or reimburse the Administrative Agent for all of its out-of-pocket costs and expenses incurred in connection with this First Amendment, any other documents prepared in connection herewith and the transactions contemplated hereby, including, without limitation, the reasonable fees and disbursements of counsel to the Administrative Agent.

6.7 Severability. Any provision of this First Amendment which is prohibited or unenforceable in any jurisdiction shall, as to such jurisdiction, be ineffective to the extent of such prohibition or unenforceability without invalidating the remaining provisions hereof, and any such prohibition or unenforceability in any jurisdiction shall not invalidate or render unenforceable such provision in any other jurisdiction.

6.8 Successors and Assigns. This First Amendment shall be binding upon and inure to the benefit of the parties hereto and their respective successors and assigns.

[signature pages follow]

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The parties hereto have caused this Agreement to be duly executed as of the day and year first above written.

BORROWER:	ATLAS RESOURCE PARTNERS, L.P.
	By:	Atlas Resource Partners GP, LLC, its general partner
		By:	/s/ Sean McGrath
		Name: Sean McGrath
		Title: Chief Financial Officer

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

ATLAS ENERGY COLORADO, LLC, a
Colorado limited liability company
ATLAS ENERGY HOLDINGS OPERATING
COMPANY, LLC, a Delaware limited liability company
ATLAS ENERGY INDIANA, LLC, an Indiana limited liability company
ATLAS ENERGY OHIO, LLC, an Ohio limited liability company
ATLAS ENERGY TENNESSEE, LLC, a
Pennsylvania limited liability company
ATLAS NOBLE, LLC, a Delaware limited liability company
ATLAS RESOURCES, LLC, a Pennsylvania limited liability company
REI-NY, LLC, a Delaware limited liability company
RESOURCE ENERGY, LLC, a Delaware limited liability company
RESOURCE WELL SERVICES, LLC, a
Delaware limited liability company
VIKING RESOURCES, LLC, a Pennsylvania limited liability company
ARP BARNETT, LLC, a Delaware limited liability company
ARP OKLAHOMA, LLC, an Oklahoma limited liability company
ARP BARNETT PIPELINE, LLC, a Delaware limited liability company
By:	/s/ Sean McGrath
Name: Sean McGrath
Title: Chief Financial Officer

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

WELLS FARGO BANK, NATIONAL ASSOCIATION, as a Lender and as Administrative Agent
By:	/s/ Matthew Coleman
	Matthew Coleman, Vice President

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

CITIBANK, N.A., as a Lender
By:	/s/ Daniel A Davis
Name:	Daniel A Davis
Title:	SVP

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

JPMORGAN CHASE BANK, N.A.,
as a Lender
By:	/s/ Jo Linda Papadakis
Name:	Jo Linda Papadakis
Title:	Authorized Officer

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

BANK OF AMERICA, N.A., as a Lender
By:	/s/ Michael Ouellet
Name:	Michael Ouellet
Title:	Director

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

JEFFERIES FINANCE LLC, as a Lender
By:	/s/ E. Joseph Hess
Name:	E. Joseph Hess
Title:	Managing Director

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

SOVEREIGN BANK, N.A., as a Lender
By:	/s/ Mark Connelly
Name:	Mark Connelly
Title:	SVP
By:	/s/ Vaughn Buck
Name:	Vaughn Buck
Title:	EVP

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

CAPITAL ONE, NATIONAL ASSOCIATION, as a Lender
By:	/s/ Peter Shen
Name:	Peter Shen
Title:	Vice President

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

DEUTSCHE BANK TRUST COMPANY AMERICAS, as a Lender
By:	/s/ Michael Getz
Name:	Michael Getz
Title:	Vice President
By:	/s/ Marcus M. Tarkington
Name:	Marcus M. Tarkington
Title:	Director

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

COMERICA BANK, as a Lender
By:	/s/ John S. Lesikar
Name:	John S. Lesikar
Title:	Assistant Vice President

SIGNATURE PAGE TO FIRST AMENDMENT TO AMENDED AND RESTATED CREDIT AGREEMENT

ATLAS RESOURCE PARTNERS, L.P.

ANNEX I

LIST OF MAXIMUM CREDIT AMOUNTS

Name of Lender	Applicable Percentage			Maximum Credit Amount
Wells Fargo Bank, National Association		15.00000000	%	$	75,000,000.00
Citibank, N.A.		15.00000000	%	$	75,000,000.00
JPMorgan Chase Bank, N.A.		12.80000000	%	$	64,000,000.00
Bank of America, N.A.		12.80000000	%	$	64,000,000.00
Deutsche Bank Trust Company Americas		12.80000000	%	$	64,000,000.00
Comerica Bank		11.20000000	%	$	56,000,000.00
Jefferies Finance LLC		8.95000000	%	$	44,750,000.00
Sovereign Bank, N.A.		8.95000000	%	$	44,750,000.00
Capital One, National Association		2.50000000	%	$	12,500,000.00
Total		100	%	$	500,000,000

Annex I-I

EX-10.2

Exhibit 10.2

JOINDER AGREEMENT

This Joinder Agreement dated as of April 18, 2012 (this “Agreement”), is between ARP Barnett, LLC, a Delaware limited liability company (“Barnett”), ARP Oklahoma, LLC, an Oklahoma limited liability company (“Oklahoma” and together with Barnett, each a “New Guarantor”, and collectively the “New Guarantors”) and Wells Fargo Bank, National Association, in its capacity as administrative agent under the Credit Agreement (defined below) (in such capacity, the “Administrative Agent”). Capitalized terms used in this Agreement without definition have the meanings assigned to those terms in the Guaranty, the Security Agreement, and the Credit Agreement.

RECITALS

A. Pursuant to an Amended and Restated Credit Agreement dated as of March 5, 2012 (as amended, amended and restated, supplemented or otherwise modified from time to time, the “Credit Agreement”), among Atlas Resource Partners, L.P., a Delaware limited partnership (the “Borrower”), the lenders party thereto from time to time (the “Lenders”), and the Administrative Agent, the Lenders agreed to make loans and other extensions of credit to the Borrower in an aggregate principal amount of up to the Maximum Credit Amounts.

B. The Borrower and/or one or more of its Subsidiaries may at any time and from time to time enter into one or more Secured Swap Agreements with one or more Secured Swap Providers (as defined in the Security Agreement, defined below).

C. The Borrower and/or one or more of its Subsidiaries may at any time and from time to time enter into an agreement in respect of Bank Products with a Bank Products Provider.

D. Pursuant to an Amended and Restated Guaranty dated as of March 5, 2012 (as amended, restated or otherwise modified from time to time, the “Guaranty”) made by the Subsidiaries of the Borrower party thereto from time to time (the “Guarantors”) in favor of the Administrative Agent for the benefit of the Secured Creditors (as defined in the Guaranty), the Guarantors have guaranteed the payment of the Indebtedness, and pursuant to an Amended and Restated Security Agreement dated as of March 5, 2012 (as amended, restated or otherwise modified from time to time, the “Security Agreement”) made by the Borrower, the Subsidiaries of Borrower party thereto from time to time (together with the Borrower, the “Grantors”), and the Agent for the benefit of the Secured Creditors (as defined in the Security Agreement), the Grantors have granted security interests in the collateral described therein as security for the Indebtedness.

E. Section 4.14 of the Guaranty and Section 9.13 of the Security Agreement provide that additional Material Subsidiaries of the Borrower may become Guarantors under the Guaranty and Grantors under the Security Agreement by execution and delivery of an instrument in the form of this Agreement. Each New Guarantor is executing this Agreement in accordance with the requirements of the Credit Agreement to become a Guarantor under the Guaranty and a Grantor under the Security Agreement.

Accordingly, the Administrative Agent and the New Guarantors agree as follows:

1

1. In accordance with Section 4.14 of the Guaranty, each New Guarantor by its signature below becomes a Guarantor under the Guaranty with the same force and effect as if originally named as a Guarantor in the Guaranty, and each New Guarantor hereby (a) ratifies, as of the date hereof, and agrees to all the terms and provisions of the Guaranty applicable to it as a Guarantor thereunder and (b) represents and warrants that the representations and warranties made by it as a Guarantor thereunder are true and correct on and as of the date hereof. Each reference to a “Guarantor” in the Guaranty will be deemed to include the New Guarantors.

2. In accordance with Section 9.13 of the Security Agreement, each New Guarantor by its signature below becomes a Grantor under the Security Agreement with the same force and effect as if originally named therein as a Grantor, and each New Guarantor hereby (a) ratifies, as of the date hereof, and agrees to all the terms and provisions of the Security Agreement applicable to it as a Grantor thereunder and (b) represents and warrants that the representations and warranties made by it as a Grantor thereunder are true and correct in all material respects on and as of the date hereof. The Schedules to the Security Agreement are hereby supplemented by the Schedules attached hereto with respect to the New Guarantors. In furtherance of the foregoing, each New Guarantor, as security for the payment and performance in full of the Secured Obligations (as defined in the Security Agreement), hereby grants to the Administrative Agent, for the ratable benefit of the Secured Creditors, a security interest in all of such New Guarantor’s right, title and interest in, to and under the Collateral (as defined in the Security Agreement) of such New Guarantor. Each reference to a “Grantor” in the Security Agreement will be deemed to include the New Guarantors.

3. If required, each New Guarantor is, simultaneously with the execution of this Agreement, executing and delivering such Security Instruments (and such other documents and instruments) as requested by the Administrative Agent in accordance with the Credit Agreement.

4. Each New Guarantor represents and warrants to the Administrative Agent that:

(a) an executed (or conformed) copy of each of the Loan Documents, the Secured Swap Agreements and the Bank Products Agreements, if any, has been made available to a Responsible Officer of such New Guarantor and such Responsible Officer has a duty to and has read these documents, and has full notice and knowledge of the terms, conditions and effects thereof. Such New Guarantor has, independently and without reliance upon any Secured Creditor or any information received from the Secured Creditors, and based upon such documents and information as such New Guarantor has deemed appropriate, made its own analysis of the transactions contemplated hereby and the Borrower, the Borrower’s business, assets, operations, prospects and condition, financial or otherwise, and any circumstances which may bear upon such transactions, the Borrower or the obligations and risks undertaken herein with respect to the Indebtedness, and decision to enter into the Guaranty. Such New Guarantor has received the advice of its attorney in entering into the Guaranty and the other Loan Documents to which it is a party. Such New Guarantor has not relied and will not rely upon any representations or warranties of the Administrative Agent not embodied in the Guaranty or any acts heretofore or hereafter taken by the Administrative Agent (including but not limited to any review by the Administrative Agent of the affairs of Borrower). Such New Guarantor has adequate means to obtain from the Borrower on a continuing basis

information concerning the financial condition and assets of the Borrower, and such New Guarantor is not relying upon any Secured Creditor to provide (and no Secured Creditor will have a duty to provide) any such information to any Guarantor either now or in the future; and

(b) the representations and warranties set forth in Article VII of the Credit Agreement are incorporated herein by reference, the same as if stated verbatim herein as representations and warranties made by such New Guarantor, and such New Guarantor, jointly and severally represents and warrants that each of such representations and warranties are true and correct (which representations and warranties shall be deemed to have been renewed at the time of each Loan under the Credit Agreement); provided that each reference in each such representation and warranty to the Borrower’s knowledge shall, for the purposes of Section 4(b), be deemed to be a reference to such New Guarantor’s knowledge.

5. This Agreement may be executed in counterparts (and by different parties hereto on different counterparts), each of which will constitute an original, but all of which when taken together will constitute a single contract.

6. Except as expressly supplemented by this Agreement, the Guaranty and the Security Agreement remain in full force and effect.

7. THIS AGREEMENT IS GOVERNED BY, AND WILL BE CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

8. This Agreement is a Loan Document for all purposes of the Credit Agreement and the other Loan Documents.

9. Each New Guarantor agrees to execute, acknowledge, deliver, file and record such further certificates, instruments and documents, and to do all other acts and things as may be requested by the Administrative Agent as necessary or advisable to carry out the intents and purposes of this Agreement, the Security Instruments and the Credit Agreement.

10. All communications and notices to any New Guarantor under the Guaranty and the Security Agreement must be in writing and given as provided in Section 4.1 of the Guaranty to the address for such New Guarantor set forth under its signature below.

11. The New Guarantors shall reimburse the Administrative Agent for its reasonable documented out of-pocket expenses in connection with this Agreement, including reasonable fees and documented expenses for legal services.

IN WITNESS WHEREOF, the New Guarantors and the Administrative Agent have duly executed this Joinder Agreement as of the day and year first above written.

ARP BARNETT, LLC
ARP OKLAHOMA, LLC
By:	/s/ Sean McGrath
Name:	Sean McGrath
Title:	Chief Financial Officer
Address:
1845 Walnut Street, 10th Floor
Philadelphia, Pennsylvania 19118
Attention: Sean McGrath

WELLS FARGO BANK, NATIONAL ASSOCIATION, as Administrative Agent
By:	/s/ Jason M. Hicks
Name:	Jason M. Hicks
Title:	Managing Director

SCHEDULE 4.3

GRANTOR INFORMATION

Grantor Name	Type of Organization	Jurisdiction of Formation	Foreign Qualification	EIN	Entity Identification Number	Chief Executive Office
ARP Barnett, LLC	Limited Liability Company	DE	Texas	90-0812567	5124746	Park Place Corporate Center One 1000 Commerce Drive Suite 400 Pittsburgh, PA 15275
ARP Oklahoma, LLC	Limited Liability Company	OK	N/A	90-0815193	3512352463	Park Place Corporate Center One 1000 Commerce Drive Suite 400 Pittsburgh, PA 15275

SCHEDULE 4.4

CHANGE IN CIRCUMSTANCES

None.

SCHEDULE 4.5

TRADE NAMES

Grantor Name	d/b/a
ARP Barnett, LLC	N/A
ARP Oklahoma, LLC	N/A

SCHEDULE 4.6

PERFECTION ACTIONS

Uniform Commercial Code Filings

1. Secretary of State of the State of Delaware with respect to ARP Barnett, LLC

2. Secretary of State of the State of Oklahoma with respect to ARP Oklahoma, LLC

Control Agreements

None

Patent, Trademark and Copyright Filings

None

SCHEDULE 4.7

OTHER FINANCING STATEMENTS

None.

SCHEDULE 4.8

LOCATION OF INVENTORY AND EQUIPMENT

Park Place Corporate Center One

1000 Commerce St., 4^th Floor

Pittsburgh, PA 15275

613 S. 4th Avenue

Mansfield, TX 76063

3500 Massillon Road, Suite 1000

Uniontown, OH 44685

SCHEDULE 4.9

CERTAIN SIGNIFICANT TRANSACTIONS

None

SCHEDULE 4.11

DEPOSIT, COMMODITIES AND SECURITIES ACCOUNTS

	Key Bank Account #		Wells Fargo Account #	Citibank Account #	JPMorgan Chase Account #	Bank of America Account #	Account Type	over $2.5MM
ARP Barnett, LLC
ARP Barnett, LLC general account		359681331674					Checking
Royalty Disbursements account		350993201705
Accounts Payable account		350993201713
ARP Oklahoma, LLC		None

SCHEDULE 4.12

COMMERCIAL TORT CLAIMS

None.

SCHEDULE 4.13

PLEDGED EQUITY INTERESTS

Issuer	Form and Jurisdiction of Organization	Type of Equity Interest Certificate Information	Beneficial Owner	% of Interests Pledged
ARP Barnett, LLC	DE LLC	Membership Interests Uncertificated	Atlas Energy Holdings Operating Company, LLC	100%
ARP Oklahoma, LLC	OK LLC	Membership Interests Uncertificated	Atlas Energy Holdings Operating Company, LLC	100%

SCHEDULE 4.15

PATENT AND TRADEMARKS

None

Mark Registration No.

EX-10.3

Exhibit 10.3

JOINDER AGREEMENT

This Joinder Agreement dated as of April 30, 2012 (this “Agreement”), is between ARP Barnett Pipeline, LLC, a Delaware limited liability company (the “New Guarantor”), and Wells Fargo Bank, National Association, in its capacity as administrative agent under the Credit Agreement (defined below) (in such capacity, the “Administrative Agent”). Capitalized terms used in this Agreement without definition have the meanings assigned to those terms in the Guaranty, the Security Agreement, and the Credit Agreement.

RECITALS

A. Pursuant to an Amended and Restated Credit Agreement dated as of March 5, 2012 (as amended, amended and restated, supplemented or otherwise modified from time to time, the “Credit Agreement”), among Atlas Resource Partners, L.P., a Delaware limited partnership (the “Borrower”), the lenders party thereto from time to time (the “Lenders”), and the Administrative Agent, the Lenders agreed to make loans and other extensions of credit to the Borrower in an aggregate principal amount of up to the Maximum Credit Amounts.

B. The Borrower and/or one or more of its Subsidiaries may at any time and from time to time enter into one or more Secured Swap Agreements with one or more Secured Swap Providers (as defined in the Security Agreement, defined below).

C. The Borrower and/or one or more of its Subsidiaries may at any time and from time to time enter into an agreement in respect of Bank Products with a Bank Products Provider.

D. Pursuant to an Amended and Restated Guaranty dated as of March 5, 2012 (as amended, restated or otherwise modified from time to time, the “Guaranty”) made by the Subsidiaries of the Borrower party thereto from time to time (the “Guarantors”) in favor of the Administrative Agent for the benefit of the Secured Creditors (as defined in the Guaranty), the Guarantors have guaranteed the payment of the Indebtedness, and pursuant to an Amended and Restated Security Agreement dated as of March 5, 2012 (as amended, restated or otherwise modified from time to time, the “Security Agreement”) made by the Borrower, the Subsidiaries of Borrower party thereto from time to time (together with the Borrower, the “Grantors”), and the Agent for the benefit of the Secured Creditors (as defined in the Security Agreement), the Grantors have granted security interests in the collateral described therein as security for the Indebtedness.

E. Section 4.14 of the Guaranty and Section 9.13 of the Security Agreement provide that additional Material Subsidiaries of the Borrower may become Guarantors under the Guaranty and Grantors under the Security Agreement by execution and delivery of an instrument in the form of this Agreement. The New Guarantor is executing this Agreement in accordance with the requirements of the Credit Agreement to become a Guarantor under the Guaranty and a Grantor under the Security Agreement.

Accordingly, the Administrative Agent and the New Guarantor agree as follows:

1. In accordance with Section 4.14 of the Guaranty, the New Guarantor by its signature below becomes a Guarantor under the Guaranty with the same force and effect as if

1

originally named as a Guarantor in the Guaranty, and the New Guarantor hereby (a) ratifies, as of the date hereof, and agrees to all the terms and provisions of the Guaranty applicable to it as a Guarantor thereunder and (b) represents and warrants that the representations and warranties made by it as a Guarantor thereunder are true and correct on and as of the date hereof. Each reference to a “Guarantor” in the Guaranty will be deemed to include the New Guarantor.

2. In accordance with Section 9.13 of the Security Agreement, the New Guarantor by its signature below becomes a Grantor under the Security Agreement with the same force and effect as if originally named therein as a Grantor, and the New Guarantor hereby (a) ratifies, as of the date hereof, and agrees to all the terms and provisions of the Security Agreement applicable to it as a Grantor thereunder and (b) represents and warrants that the representations and warranties made by it as a Grantor thereunder are true and correct in all material respects on and as of the date hereof. The Schedules to the Security Agreement are hereby supplemented by the Schedules attached hereto with respect to the New Guarantor. In furtherance of the foregoing, the New Guarantor, as security for the payment and performance in full of the Secured Obligations (as defined in the Security Agreement), hereby grants to the Administrative Agent, for the ratable benefit of the Secured Creditors, a security interest in all of the New Guarantor’s right, title and interest in, to and under the Collateral (as defined in the Security Agreement) of the New Guarantor. Each reference to a “Grantor” in the Security Agreement will be deemed to include the New Guarantor.

3. If required, the New Guarantor is, simultaneously with the execution of this Agreement, executing and delivering such Security Instruments (and such other documents and instruments) as requested by the Administrative Agent in accordance with the Credit Agreement.

4. The New Guarantor represents and warrants to the Administrative Agent that:

(a) an executed (or conformed) copy of each of the Loan Documents, the Secured Swap Agreements and the Bank Products Agreements, if any, has been made available to a Responsible Officer of the New Guarantor and such Responsible Officer has a duty to and has read these documents, and has full notice and knowledge of the terms, conditions and effects thereof. The New Guarantor has, independently and without reliance upon any Secured Creditor or any information received from the Secured Creditors, and based upon such documents and information as the New Guarantor has deemed appropriate, made its own analysis of the transactions contemplated hereby and the Borrower, the Borrower’s business, assets, operations, prospects and condition, financial or otherwise, and any circumstances which may bear upon such transactions, the Borrower or the obligations and risks undertaken herein with respect to the Indebtedness, and decision to enter into the Guaranty. The New Guarantor has received the advice of its attorney in entering into the Guaranty and the other Loan Documents to which it is a party. The New Guarantor has not relied and will not rely upon any representations or warranties of the Administrative Agent not embodied in the Guaranty or any acts heretofore or hereafter taken by the Administrative Agent (including but not limited to any review by the Administrative Agent of the affairs of Borrower). The New Guarantor has adequate means to obtain from the Borrower on a continuing basis information concerning the financial condition and assets of the Borrower, and the New Guarantor is

not relying upon any Secured Creditor to provide (and no Secured Creditor will have a duty to provide) any such information to any Guarantor either now or in the future; and

(b) the representations and warranties set forth in Article VII of the Credit Agreement are incorporated herein by reference, the same as if stated verbatim herein as representations and warranties made by the New Guarantor, and the New Guarantor, jointly and severally represents and warrants that each of such representations and warranties are true and correct (which representations and warranties shall be deemed to have been renewed at the time of each Loan under the Credit Agreement); provided that each reference in each such representation and warranty to the Borrower’s knowledge shall, for the purposes of Section 4(b), be deemed to be a reference to such New Guarantor’s knowledge.

5. This Agreement may be executed in counterparts (and by different parties hereto on different counterparts), each of which will constitute an original, but all of which when taken together will constitute a single contract.

6. Except as expressly supplemented by this Agreement, the Guaranty and the Security Agreement remain in full force and effect.

7. THIS AGREEMENT IS GOVERNED BY, AND WILL BE CONSTRUED IN ACCORDANCE WITH, THE LAWS OF THE STATE OF NEW YORK.

8. This Agreement is a Loan Document for all purposes of the Credit Agreement and the other Loan Documents.

9. The New Guarantor agrees to execute, acknowledge, deliver, file and record such further certificates, instruments and documents, and to do all other acts and things as may be requested by the Administrative Agent as necessary or advisable to carry out the intents and purposes of this Agreement, the Security Instruments and the Credit Agreement.

10. All communications and notices to the New Guarantor under the Guaranty and the Security Agreement must be in writing and given as provided in Section 4.1 of the Guaranty to the address for the New Guarantor set forth under its signature below.

11. The New Guarantor shall reimburse the Administrative Agent for its reasonable documented out of-pocket expenses in connection with this Agreement, including reasonable fees and documented expenses for legal services.

IN WITNESS WHEREOF, the New Guarantor and the Administrative Agent have duly executed this Joinder Agreement as of the day and year first above written.

ARP BARNETT PIPELINE, LLC
By:	/s/ Sean McGrath
Name:	Sean McGrath
Title:	Chief Financial Officer
Address: 1845 Walnut Street, 10th Floor Philadelphia, Pennsylvania 19118 Attention: Sean McGrath

[Signature Page to Joinder Agreement]

WELLS FARGO BANK, NATIONAL ASSOCIATION, as Administrative Agent
By:	/s/ Matthew W. Coleman
Name:	Matthew W. Coleman
Title:	Vice President

[Signature Page to Joinder Agreement]

SCHEDULE 4.3

GRANTOR INFORMATION

Grantor Name	Type of Organization	Jurisdiction of Formation	Foreign Qualification	EIN	Organizational ID Number	Chief Executive Office
ARP Barnett Pipeline, LLC	Limited Liability Company	DE	N/A	61-1682295	5145069	Park Place Corporate Center One 1000 Commerce Drive Suite 400 Pittsburgh, PA 15275

SCHEDULE 4.4

CHANGE IN CIRCUMSTANCES

None.

SCHEDULE 4.5

TRADE NAMES

Grantor Name	d/b/a
ARP Barnett Pipeline, LLC	N/A

SCHEDULE 4.6

PERFECTION ACTIONS

Uniform Commercial Code Filings

1. Secretary of State of the State of Delaware with respect to ARP Barnett Pipeline, LLC

Control Agreements

None.

Patent, Trademark and Copyright Filings

None.

SCHEDULE 4.7

OTHER FINANCING STATEMENTS

None.

SCHEDULE 4.8

LOCATION OF INVENTORY AND EQUIPMENT

Park Place Corporate Center One

1000 Commerce St., 4^th Floor

Pittsburgh, PA 15275

613 S. 4th Avenue

Mansfield, TX 76063

SCHEDULE 4.9

CERTAIN SIGNIFICANT TRANSACTIONS

None.

SCHEDULE 4.11

DEPOSIT, COMMODITIES AND SECURITIES ACCOUNTS

None

	Key Bank Account #	Wells Fargo Account #	Citibank Account #	JPMorgan Chase Account #	Bank of America Account #	Account Type	over $2.5MM
ARP Barnet Pipeline, LLC

SCHEDULE 4.12

COMMERCIAL TORT CLAIMS

None.

SCHEDULE 4.13

PLEDGED EQUITY INTERESTS

Issuer	Form and Jurisdiction of Organization	Type of Equity Interest Certificate Information	Beneficial Owner	% of Interests Pledged
ARP Barnett Pipeline, LLC	DE LLC	Membership Interests Uncertificated	ARP Barnett, LLC	100%

SCHEDULE 4.15

PATENT AND TRADEMARKS

None.

Mark Registration No.

EX-99.1

Exhibit 99.1

NEWS RELEASE

Contact:	Brian Begley
	Vice President - Investor Relations
	(877) 280-2857
	(215) 405-2718 (fax)

ATLAS RESOURCE PARTNERS, L.P. ANNOUNCES COMPLETION OF

BARNETT SHALE ASSET ACQUISITION

PHILADELPHIA, PA – April 30, 2012 – Atlas Resource Partners, L.P. (NYSE: ARP) announces the completion of its acquisition of approximately 277 bcfe of proved reserves, including undeveloped drilling locations, in the Barnett Shale in Texas from Carrizo Oil & Gas (NASD: CRZO). The total consideration for the transaction was approximately $190 million, subject to final post-closing adjustments, funded by a private placement of approximately $120 million of common units and approximately $70 million borrowed against ARP’s revolving credit facility. Concurrent with the closing of the transaction, ARP received authorization from its lending group to expand the capacity on its revolving credit line to a borrowing base of $250 million.

Citigroup acted as financial advisor and sole placement agent in connection with the private placement on the transaction, and Jones Day and Ledgewood acted as legal advisors on the transaction.

An investor presentation which provides details on the Barnett Shale transaction is available on the company’s website, www.atlasresourcepartners.com, in the Investor Relations section under the Presentations menu.

The securities offered in the private placement will not be and have not yet been registered under the Securities Act of 1933 and may not be offered or sold in the United States absent registration or an applicable exemption from registration requirements. This press release shall not constitute an offer to sell or the solicitation of an offer to buy, nor shall there be any sale of these securities in any state in which the offer, solicitation or sale would be unlawful prior to the registration or qualification under the securities laws of any such state.

Management does not forecast certain items, including GAAP revenues, depreciation, amortization, and non-cash changes in derivatives, and therefore is unable to provide forecasted Net Income, a comparable GAAP measure, for the periods presented. The reconciling items

between these non-GAAP measures and Net Income are expected to be similar to those for the current periods presented and are not expected to be significant to ARP’s cash flows.

* * *

Atlas Resource Partners, L.P. (NYSE: ARP) is an exploration & production master limited partnership which owns an interest in over 8,600 producing natural gas and oil wells, representing approximately 450 Bcfe of net proved reserves, primarily in Appalachia and the Barnett Shale in Texas. ARP is also the largest sponsor of natural gas and oil investment partnerships in the U.S. For more information, please visit our website at www.atlasresourcepartners.com, or contact Investor Relations at InvestorRelations@atlasenergy.com.

Atlas Energy, L.P. (NYSE: ATLS) is a master limited partnership which owns all of the general partner interest, all the incentive distribution rights and approximately 64% of the limited partner interests in its upstream oil & gas subsidiary, Atlas Resource Partners, L.P. Additionally, Atlas Energy owns and operates the general partner of its midstream oil & gas subsidiary, Atlas Pipeline Partners, L.P., through all of the general partner interest, all the incentive distribution rights and an approximate 11% limited partner interest. For more information, please visit our website at www.atlasenergy.com, or contact Investor Relations at InvestorRelations@atlasenergy.com.

Cautionary Note Regarding Forward-Looking Statements

This document contains forward-looking statements that involve a number of assumptions, risks and uncertainties that could cause actual results to differ materially from those contained in the forward-looking statements. ATLS and Atlas Resource Partners caution readers that any forward-looking information is not a guarantee of future performance. Such forward-looking statements include, but are not limited to, statements about future financial and operating results, resource potential, ATLS’ and Atlas Resource Partners’ plans, objectives, expectations and intentions and other statements that are not historical facts. Risks, assumptions and uncertainties that could cause actual results to materially differ from the forward-looking statements include, but are not limited to, the expected financial results of Atlas Resource Partners, which is dependent on future events or developments; assumptions and uncertainties associated with general economic and business conditions; changes in commodity prices; changes in the costs and results of drilling operations; uncertainties about estimates of reserves and resource potential; inability to obtain capital needed for operations; ATLS’ and Atlas Resource Partners’ level of indebtedness; changes in government environmental policies and other environmental risks; the availability of drilling equipment and the timing of production; and tax consequences of business transactions. In addition, ATLS and Atlas Resource Partners are subject to additional risks, assumptions and uncertainties detailed from time to time in the reports filed by ATLS and Atlas Resource Partners with the U.S. Securities and Exchange Commission, including the risks, assumptions and uncertainties described in their quarterly reports on Form 10-Q, reports on Form 8-K and annual reports on Form 10-K. Forward-looking statements speak only as of the date hereof,

and neither ATLS nor Atlas Resource Partners assumes any obligation to update such statements, except as may be required by applicable law.