Willis Lease Finance Corporation, together its subsidiaries, provides aviation services. It primarily focuses on providing operating leases of commercial aircraft engines and other aircraft-related equipment to air carriers, manufacturers, and overhaul/repair facilities worldwide. Its engine portfolio consists of noise-compliant stage III commercial jet engines. As of December 31, 2009, the company had a total lease portfolio of 169 aircraft engines and related equipment, 4 aircraft, and 3 spare parts packages with 58 lessees in 33 countries. It also engages in the purchase and resale of commercial aircraft engines. The company managed a total lease portfolio of 11 engines and related equipment for other parties. Willis Lease Finance Corporation primarily serves commercial aircraft operators, as well as maintenance, repair, and overhaul organizations. The company was founded in 1985 and is based in Novato, California.