Willis Lease Finance Corporation, together with its subsidiaries, leases large and regional spare commercial aircraft engines, auxiliary power units, and aircraft worldwide. The company operates through two segments, Leasing and Related Operations, and Spare Parts Sales. It also purchases and resells commercial aircraft engines; and sells aircraft engine parts and materials. The company offers noise-compliant Stage III commercial jet engines. It serves airlines and aircraft engine manufacturers, as well as maintenance, repair, and overhaul providers. As of December 31, 2017, the company had a total lease portfolio of 225 engines and related equipment, 16 aircraft, and 7 other leased parts and equipment with 80 lessees in 43 countries; and managed a total lease portfolio of 437 engines and related equipment on behalf of other parties, as well as 393 engines. Willis Lease Finance Corporation was founded in 1985 and is headquartered in Coconut Creek, Florida.