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

Exhibit 10(r)

CONTRIBUTION, CONVEYANCE AND ASSUMPTION AGREEMENT

DATED DECEMBER 18, ▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇ ▇▇▇▇▇▇▇, INC., ATLAS

ENERGY RESOURCES, LLC, AND ATLAS ENERGY OPERATING

COMPANY, LLC