Willis Lease Finance Corporation is a lessor of commercial aircraft engines. The Company is engaged in acquisition of commercial aircraft engines and managing those engines for lease rent and maintenance reserve revenues, as well as through management fees earned for managing aircraft engines owned by other parties. As of December 31, 2010, the Company had total lease portfolio consisting of 179 engines and related equipment, three aircraft and four spare parts packages with 62 lessees in 35 countries. As of December 31, 2010, the Company managed a total lease portfolio of 16 engines and related equipment for other parties. It also seeks, from time to time, to act as leasing agent of engines for other parties and it also owns a portfolio of aircraft, which it leases. Its engine portfolio consists of commercial jet engines manufactured by CFMI, General Electric, Pratt & Whitney, Rolls Royce and International Aero Engines.