A senior official at the U.S. export credit agency says he would like to see the government take a smaller role in underwriting aircraft loans, but issued a strong defense of the program’s effectiveness.

“Nothing would make me happier if everyone else took bigger slices” of aircraft loans, said Robert Morin, vice president for transportation at the Export-Import Bank of the United States. “Clearly it’s not healthy in the long term for export credit agencies to be doing so much.”

Morin’s comments to the International Society of Transport Aircraft Trading conference (ISTAT) in Phoenix came as the U.S. Senate voted 55-45 to reject an amendment to a jobs bill that would reauthorize the bank’s authority, which expires May 31. The bank promotes U.S. exports by guaranteeing loans for manufactured products sold to foreign customers. But Republican critics have complained that it has retained an outsized role in the aircraft market now that the private credit market has recovered from the crisis of 2008-09.

The Ex-Im guaranteed financing for a record $11 billion worth of aircraft sales in 2011, and is expected to have record support of aircraft lessors in 2012. But Morin issued a spirited defense of the aircraft financing, noting that in the last 25 years the agency has sustained a loss on only one aircraft worth $4 million. That equates to a loss ratio of five-one thousands of one percent.

Morin also noted that the bank helps U.S. aircraft manufacturers sell into regions such as South America and Africa. “Some of those are places where the capital markets might not be ready to step up and do things,” he said.

Informed at the end of his presentation of the Senate vote by a member of the ISTAT audience, Morin declined to react. “I’m really just a humble financier,” he said. “I don’t do politics, so I’m not sure what I can say to that.”