DC Air, by aligning with American, would become a rival of United's rather than a partner.

American's new relationship with DC Air may also concern regulators.

His original agreement with United prevented him from making a profit from selling DC Air for at least three years.

Mr. Johnson plans to create a regional carrier called DC Air.

United proposed spinning off DC Air as a way of addressing Federal antitrust concerns.

But "wet leasing," which is what DC Air would do, is akin to hiring a chauffeured car.

In the merger application, Mr. James has been representing the prospective owner of DC Air.

United agreed to provide airplanes and a host of other services to get DC Air started.

Mr. Johnson subsequently decided that he would sell as much as 49 percent of DC Air to a rival carrier.

American, in turn, agreed to buy 49 percent of DC Air from Mr. Johnson for $82.4 million.