US Airways Group Inc. pilots asked federal regulators to investigate the carrier’s proposed swap of flight slots with Delta Air Lines Inc. at two airports, saying the plan may result in higher fares and job losses.

Under the agreement disclosed Aug. 12, Delta would get 125 takeoff and landing slots at New York’s LaGuardia Airport, while US Airways would gain space for 42 round trips at Ronald Reagan Washington National Airport. The plan raises antitrust concerns, the US Airline Pilots Association said in a statement yesterday.

The swap boosts Delta’s strategy of focusing on New York, where it has a base for international flights at Kennedy airport and is second in passengers in the region. It also aids US Airways’ plan to cut 1,000 jobs as it scales back service in some cities to concentrate on Washington National and hub airports in Philadelphia, Phoenix, and Charlotte, N.C.

“Those conditions raise the prospect of higher fares and, if history repeats itself, a reduction in service to smaller communities,’’ Mike Cleary, the union president, said in the statement.

The agreement “places a great burden on many of US Airways’ New York-based employees whose jobs will be eliminated,’’ said the union, which represents more than 5,000 of the airline’s pilots.