Four Airbus SAS A380 passenger jets being leased to Emirates Airline are the first of their kind to be used as collateral in a U.S. corporate bond offering, according to a person familiar with the transaction. Doric Nimrod Air Finance Alpha Ltd., a leasing company, sold $587.5 million of debt secured by four A380s to be operated by Dubai-based Emirates, according to data compiled by Bloomberg. The two-part offering was the first sale of dollar-denominated bonds backed by a non-U.S. airline's planes, said the person, who wasn't authorized to discuss the deal publicly.