Exhibit 10.1

Execution Version

THIRD AMENDMENT

TO

CREDIT AGREEMENT

AMONG

REX ENERGY CORPORATION,

as Borrower,

KEYBANK NATIONAL ASSOCIATION,

as Administrative Agent,

and

The Lenders Signatory Hereto

Effective as of April 20, 2009

THIRD AMENDMENT TO CREDIT AGREEMENT

This THIRD AMENDMENT TO CREDIT AGREEMENT (this “Third Amendment”) executed effective as of the 20th of April, 2009 (the “Third Amendment Effective Date”) is among REX ENERGY CORPORATION, a corporation formed under the laws of the State of Delaware (the “Borrower”); KEYBANK NATIONAL ASSOCIATION, as administrative agent for the Lenders (in such capacity, together with its successors, the “Administrative Agent”), and the Lenders signatory hereto.

Recitals

A. The Borrower, the Administrative Agent and the Lenders are parties to that certain Credit Agreement dated as of September 28, 2007, as amended by that certain First Amendment dated as of April 14, 2008, as amended by that certain Second Amendment dated as of December 23, 2008 (the “Credit Agreement”), pursuant to which the Lenders have made certain credit available to and on behalf of the Borrower.

B. The Borrower, the Administrative Agent and the Lenders have agreed to amend certain provisions of the Credit Agreement.

C. The Lenders have redetermined the Borrowing Base in the amount set forth herein.

D. 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 Third Amendment, shall have the meaning ascribed such term in the Credit Agreement. Unless otherwise indicated, all section references in this Third Amendment refer to the Credit Agreement.

Section 2. Amendments to Credit Agreement.

2.1 Amendments to Section 1.02. Section 1.02 is hereby amended by deleting the defined term “Applicable Margin” and replacing it with the following:

“‘Applicable Margin’ means, for any day, with respect to any ABR Loan or Eurodollar Loan, or with respect to the Commitment Fee Rate, as the case may be, the rate per annum set forth in the Borrowing Base Utilization Grid below based upon the Borrowing Base Utilization Percentage then in effect:

Borrowing Base Utilization Grid
Borrowing Base Utilization Percentage	<33.0	%	³ 33.0	%	³ 66.0	%	³ 90.0	%
			<66.0	%	<90.0	%
Eurodollar Loans	1.750	%	2.000	%	2.250	%	2.500	%
ABR Loans	0.500	%	0.750	%	1.000	%	1.250	%
Commitment Fee Rate	0.375	%	0.375	%	0.500	%	0.500	%

Page 2

Each change in the Applicable Margin shall apply during the period commencing on the effective date of such change and ending on the date immediately preceding the effective date of the next such change, provided, however, that if at any time the Borrower fails to deliver a Reserve Report pursuant to Section 8.12(a), then the “Applicable Margin” means the rate per annum set forth on the grid when the Borrowing Base Utilization Percentage is at its highest level until the day that such Reserve Report is delivered to the Administrative Agent, and as of such delivery date and until the effective date of the next change in the Applicable Margin, the Applicable Margin shall be based on the Borrowing Base reflected by such Reserve Report.”

Section 3. Borrowing Base.

3.1. Borrowing Base. Pursuant to Section 2.07 of the Credit Agreement, the Borrowing Base is hereby maintained at $80,000,000 until the next Redetermination Date, subject to further adjustments from time to time pursuant to Section 8.13(c) or Section 9.12.

Section 4. Conditions Precedent. The effectiveness of this Third Amendment is subject to the receipt by the Administrative Agent of the following documents and satisfaction of the other conditions provided in this Section 4, each of which shall be reasonably satisfactory to the Administrative Agent in form and substance:

4.1 Third Amendment. The Administrative Agent shall have received multiple counterparts as requested of this Third Amendment from the Borrower and each Lender.

4.2 Payment of Outstanding Invoices. Payment by the Borrower to the Administrative Agent of all fees and other amounts due and payable on or prior to the Third Amendment Effective Date, including, to the extent invoiced, reimbursement or payment of all out-of-pocket expenses required to be reimbursed or paid by the Borrower.

4.3 No Default. No Default or Event of Default shall have occurred and be continuing as of the Third Amendment Effective Date.

Section 5. Representations and Warranties; Etc. The Borrower hereby affirms: (a) that as of the date of execution and delivery of this Third Amendment, all of the representations and warranties contained in each Loan Document to which the Borrower is a party are true and correct in all material respects as though made on and as of the Third Amendment Effective Date (unless made as of a specific earlier date, in which case, was true as of such date); and (b) that after giving effect to this Third Amendment and to the transactions contemplated hereby, no Defaults exist under the Loan Documents or will exist under the Loan Documents.

Page 3

Section 6. Miscellaneous.

6.1 Confirmation. The provisions of the Credit Agreement (as amended by this Third Amendment) shall remain in full force and effect in accordance with its terms following the effectiveness of this Third Amendment.

6.2 Ratification and Affirmation of the Borrower. The Borrower hereby expressly (a) acknowledges the terms of this Third Amendment, (b) ratifies and affirms its obligations under the Credit Agreement and the other Security Instruments to which it is a party, and (c) acknowledges, renews and extends its continued liability under the Credit Agreement and the other Security Instruments to which it is a party remains in full force and effect with respect to the Indebtedness as amended hereby.

6.3 Counterparts. This Third 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.

6.4 Limited Waiver. Neither the execution by the Administrative Agent or the Lenders of this Third Amendment, nor any other act or omission by the Administrative Agent or the Lenders or their officers in connection herewith, shall be deemed a waiver by the Administrative Agent or the Lenders of any defaults which may exist, or which may occur in the future under the Credit Agreement and/or the other Loan Documents, or any future defaults of the same provision waived hereunder (collectively “Other Violations”). Similarly, nothing contained in this Third Amendment shall directly or indirectly in any way whatsoever either: (a) impair, prejudice or otherwise adversely affect the Administrative Agent’s or the Lenders’ right at any time to exercise any right, privilege or remedy in connection with the Loan Documents with respect to any Other Violations, (b) amend or alter any provision of the Credit Agreement (except as specifically amended herein), the other Loan Documents, or any other contract or instrument, or (c) constitute any course of dealing or other basis for altering any obligation of the Borrower or any right, privilege or remedy of the Administrative Agent or the Lenders under the Credit Agreement, the other Loan Documents, or any other contract or instrument. Nothing in this Third Amendment shall be construed to be a consent by the Administrative Agent or the Lenders to any Other Violations.

6.5 No Oral Agreement. THIS WRITTEN THIRD 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.

Page 4

6.6 Governing Law. THIS THIRD 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 TEXAS.

6.7 Release of Lenders. IN CONSIDERATION OF THIS THIRD AMENDMENT AND, SUBJECT TO THE CONDITIONS STATED HEREIN, THE BORROWER HEREBY RELEASES, ACQUITS, FOREVER DISCHARGES, AND COVENANTS NOT TO SUE, THE ADMINISTRATIVE AGENT AND EACH OF THE LENDERS, ALONG WITH ALL OF THEIR BENEFICIARIES, OFFICERS, DIRECTORS, AGENTS, EMPLOYEES, SERVANTS, ATTORNEYS AND REPRESENTATIVES, AS WELL AS THEIR RESPECTIVE HEIRS, EXECUTORS, LEGAL REPRESENTATIVES, ADMINISTRATORS, PREDECESSORS IN INTEREST, SUCCESSORS AND ASSIGNS (EACH INDIVIDUALLY, A “RELEASED PARTY” AND COLLECTIVELY, THE “RELEASED PARTIES”) FROM ANY AND ALL CLAIMS, DEMANDS, DEBTS, LIABILITIES, SUITS, OFFSETS AGAINST THE INDEBTEDNESS EVIDENCED BY THE LOAN DOCUMENTS AND ACTIONS, CAUSES OF ACTION OR CLAIMS FOR RELIEF OF WHATEVER KIND OR NATURE, WHETHER KNOWN OR UNKNOWN, SUSPECTED OR UNSUSPECTED BY BORROWER OR ANY OBLIGOR, WHICH BORROWER, ANY OBLIGOR, OR ANY SUBSIDIARY MAY HAVE OR WHICH MAY HEREAFTER ACCRUE RELATED TO ANY ACTIONS OR FACTS OCCURRING PRIOR TO THE THIRD AMENDMENT EFFECTIVE DATE AGAINST ANY RELEASED PARTY, FOR OR BY REASON OF ANY MATTER, CAUSE OR THING WHATSOEVER OCCURRING ON OR PRIOR TO THE THIRD AMENDMENT EFFECTIVE DATE, WHICH RELATE TO, IN WHOLE OR IN PART, DIRECTLY OR INDIRECTLY THE CREDIT AGREEMENT, ANY HEDGING AGREEMENT, ANY NOTE, ANY SECURITY INSTRUMENT, ANY OTHER LOAN DOCUMENT OR THE TRANSACTIONS EVIDENCED THEREBY, INCLUDING, WITHOUT LIMITATION, ANY DISBURSEMENTS UNDER THE CREDIT AGREEMENT, ANY HEDGING AGREEMENT, ANY NOTES, THE NEGOTIATION OF ANY OF THE CREDIT AGREEMENT, THE SWAP AGREEMENTS, THE NOTES, OR THE OTHER LOAN DOCUMENTS, THE TERMS THEREOF, OR THE APPROVAL, ADMINISTRATION, ENFORCEMENT OR SERVICING THEREOF.

Page 5

IN WITNESS WHEREOF, the parties hereto have caused this Third Amendment to be duly executed effective as of the Third Amendment Effective Date.

BORROWER:	REX ENERGY CORPORATION
	By:	/s/ Benjamin W. Hulburt
	Name:	Benjamin W. Hulburt
	Title:	President and Chief Executive Officer
ADMINISTRATIVE AGENT:	KEYBANK NATIONAL ASSOCIATION,
	as Administrative Agent and Lender
	By:	/s/ Todd Coker
	Name:	Todd Coker
	Title:	Assistant Vice President

Third Amendment

Signature Page - 1

LENDERS:	BNP PARIBAS
	By:	/s/ Betsy Jocher
	Name:	Betsy Jocher
	Title:	Director
	By:	/s/ Polly Schott
	Name:	Polly Schott
	Title:	Director

Third Amendment

Signature Page - 2

SOVEREIGN BANK
By:	/s/ Robert D. Lanigan
Name:	Robert D. Lanigan
Title:	Senior Vice President

Third Amendment

Signature Page - 3

ALLIED IRISH BANK
By:	/s/ David O’Driscoll
Name:	David O’Driscoll
Title:	AVP
By:	/s/ Robert Moyle
Name:	Rob Moyle
Title:	SVP

Third Amendment

Signature Page - 4

M&T BANK
By:	/s/ David Ladori
Name:	David Ladori
Title:	Vice President

Third Amendment

Signature Page - 5

CAPITAL ONE, N.A.
By:	/s/ Peter Shen
Name:	Peter Shen
Title:	Assistant Vice President Capital One Bank, N.A.

Third Amendment

Signature Page - 6