NEW YORK — Delta Air Lines Inc. plans a massive flight expansion out of New York's LaGuardia airport, hoping to improve its competitive edge against its two biggest rivals in one of the nation's most important air travel markets.

Delta said Friday that the additions make it the biggest airline between the New York area and other cities in the U.S., as it adds routes that target American Airlines and put it in a better position to compete against United Continental. That should help it grab more high-paying business travelers, a critical passenger segment in major cities like New York.

The list of added cities reads like a map of the hubs of competing airlines. Delta is adding Miami and Dallas, both American Airlines hubs. It will also fly to Houston and Denver, which are United hubs, and Charlotte, N.C. — a hub for US Airways. In all, it will add more than 100 flights to 29 new destinations.

By next summer Delta expects to operate 264 daily flights from LaGuardia — the smallest of the New York area's three main airports. Those flights will go to more than 60 cities, which Delta says is more than any other airline. Currently Delta operates flights to 35 cities out of that airport.

United and Continental's merger into the world's largest airline put Delta in second-place by traffic. Expanding in a key business market like New York will help it compete against the larger airline.

"It's about increasing Delta's overall appeal and utility to the high-yield business traveler," said Henry Harteveldt, co-founder of Atmosphere Research Group in San Francisco. "Delta is going for scope of service, rather than always having the largest number of flights to a smaller network of cities."

Gail Grimmett, Delta's senior vice president of New York operations, thinks the convenience of LaGuardia will be a major deciding factor for business travelers debating between flying with Delta or United, which has a hub in nearby Newark, N.J.

As it adds flights, Delta will expand into LaGuardia's Terminal C in addition to its existing operation at Terminal D. The Atlanta-based airline will spend $100 million on the expansion. Delta will continue its shuttle service to Chicago, Boston and Washington out of the airport's Marine Air Terminal.

Delta obtained the new flying rights in a deal with US Airways Group Inc. Delta gave up some of its flying rights at Washington's Reagan National airport, which US Airways wanted, in exchange for some of that airline's rights at LaGuardia. The exchange of flying rights happens in two rounds, on March 25 and July 11. As a result some of Delta's new LaGuardia flights start in May, the rest in July.

US Airways said it will announce its plans for expanded Washington flying in January.

Delta has said it will cut overall flying by as much as 3 percent next year. CEO Richard Anderson said the new flying at LaGuardia will be offset by reduced flying in Washington.

Shares of Atlanta-based Delta rose 43 cents, or 5 percent, to close at $9.02. Shares of United Continental Holdings Inc. rose 60 cents, or 2.9 percent, to close at $21.24. US Airways Group Inc. shares rose 47 cents, or 8.2 percent, to close at $6.18.

Freed reported from Minneapolis. AP Airlines Writer David Koenig in Dallas contributed to this report.