For more than 75 years, the U.S. Export-Import Bank has promoted American-made goods, supporting billions of dollars in financing for foreign buyers in industries that include construction, medical technology and renewable energy.

Airplane financing comprises the bulk of the federal agency’s annual lending, with outstanding loans topping more than $75 billion in 2010, according to court papers in the U.S. District Court for the District of Columbia. The bank considers aviation one of a handful of key industries for U.S. export growth.