Delta Air Lines plans to roughly double its flights at New York’s LaGuardia Airport -- which it will call a new domestic hub -- while cutting flights at Washington’s Reagan National Airport, the airline said Wednesday.

The move is part of a deal Atlanta-based Delta has struck with US Airways to swap flying rights at LaGuardia and Reagan National. It calls for Delta to give 42 operating “slot pairs,” or rights for one takeoff and one landing, at Reagan National to US Airways. In exchange, Delta will get 125 of US Airways’ operating slot pairs at LaGuardia.

Federal regulators have to sign off, a process expected to take until early 2010.

Flights at LaGuardia, Reagan and a few other congested airports are restricted using government-allocated slots.

With the deal, Delta would increase the number of slot pairs it has at LaGuardia from 147 to 272 and would leapfrog American Airlines as the largest carrier at the airport.

LaGuardia has long been the “preferred domestic airport” in New York because of its convenience to Manhattan, said Delta spokesman Kent Landers. He said the LaGuardia expansion will not affect Delta’s presence in Atlanta.

Delta will continue to operate a hub and international gateway at New York’s John F. Kennedy International Airport.

The added slots will enable Delta to more than double the number of routes offered to and from LaGuardia. The airline will start a nearly $40 million construction project to connect terminals used by Delta and US Airways. Delta plans to consolidate its operation, including Delta Shuttle, into the expanded main terminal facility in 2010 with a dedicated check-in area for elite, business class, first class and Shuttle customers.

Traditionally, airline hubs are connecting points where many, if not most, travelers are transferring between flights. LaGuardia primarily serves people who are starting or finishing their trips in New York, so it won’t fit that mold. But Landers said there will be opportunities for some regional connections.

Delta said it will “continue to invest” in its operations at JFK, where it has more than 200 daily departures. Some travelers connecting in New York travel between the LaGuardia and JFK airports using ground transportation.

At Reagan National, Delta’s slot pairs would drop from 97 to 55. Delta said the deal will not affect its Shuttle service at LaGuardia and Reagan. No specific flight or route cuts have yet been announced.

As part of the deal, Delta will also give US Airways some of its international route authorities to Brazil and Japan, but Delta said that will not lead to any “material” flight schedule changes for passengers. That’s partly because Delta will still maintain access to Brazil and Delta is eliminating cargo freighter service to Japan at the end of this year.

Delta said its employees at Reagan will have opportunities to transfer to other locations in the Washington area and elsewhere.