CONTRIBUTION, CONVEYANCE AND ASSUMPTION AGREEMENT DATED DECEMBER 18, 2006 AMONG ATLAS AMERICA, INC., ATLAS ENERGY RESOURCES, LLC, AND ATLAS ENERGY OPERATING COMPANY, LLC
CONTRIBUTION, CONVEYANCE AND ASSUMPTION AGREEMENT DATED DECEMBER 18, 2006 AMONG ATLAS AMERICA, INC., ATLAS ENERGY RESOURCES, LLC, AND ATLAS ENERGY OPERATING COMPANY, LLC