REVOLVING CREDIT AGREEMENT DATED AS OF DECEMBER 18, 2006 AMONG ATLAS ENERGY OPERATING COMPANY, LLC, AS BORROWER; AER PIPELINE CONSTRUCTION, INC., AIC, LLC, ATLAS AMERICA, LLC, ATLAS ENERGY OHIO, LLC, ATLAS ENERGY RESOURCES, LLC, ATLAS NOBLE, LLC,...

Exhibit 10.27

REVOLVING CREDIT AGREEMENT DATED AS OF DECEMBER 18, 2006 AMONG ATLAS ENERGY OPERATING COMPANY, LLC, AS BORROWER; AER PIPELINE CONSTRUCTION, INC., AIC, LLC, ATLAS AMERICA, LLC, ATLAS ENERGY OHIO, LLC, ATLAS ENERGY RESOURCES, LLC, ATLAS NOBLE, LLC, ATLAS RESOURCES, LLC, REI-NY, LLC, RESOURCE ENERGY, LLC, RESOURCE WELL SERVICES, LLC, AND VIKING RESOURCES LLC AS GUARANTORS; WACHOVIA BANK, NATIONAL ASSOCIATION AS ADMINISTRATIVE AGENT AND ISSUING BANK; BANK OF AMERICA, N.A. AND COMPASS BANK AS CO-SYNDICATION AGENTS; BANK OF OKLAHOMA, N.A., U.S. BANK, NATIONAL ASSOCIATION AND BNP PARIBAS AS CO-DOCUMENTATION AGENTS AND THE LENDERS SIGNATORY HERETO $250,000,000 SENIOR SECURED REVOLVING CREDIT FACILITY WACHOVIA CAPITAL MARKETS, LLC AS LEAD ARRANGER