By the fall, Delta said it will have increased or launched service from New York’s Kennedy and LaGuardia airports to 30 cities, the airline said Tuesday.
Delta said it is encouraged by a rebound in business travel.
"We continue to see corporate travel demand improve across our network, particularly in New York," said Gail Grimmett, Delta's senior vice president for New York operations. "With the economy rebounding, our New York customers can look forward to an expansion of flights to both domestic and international destinations."
On Sept. 19, Delta will add a daily flight between Kennedy and London Heathrow, expanding its service on that route to three times daily. The Boeing 767 service will have full-flat beds in business class.
As part of its joint venture with Air France-KLM, Delta has reinstated a third daily flight between New York and Amsterdam.
As previously announced, Delta will introduce year-round, nonstop service to Copenhagen, Denmark, and Stockholm, Sweden, on May 27.
Last week, the airline reinstated year-round service from Kennedy to Shannon, Ireland, and Manchester, England, and expanded Brussels service to daily.
In June, larger aircraft will be used on flights from New York to Athens; Istanbul; Milan; Moscow; Nice, France; Tel Aviv; and Tokyo Narita.
Domestically, three new business markets will be added beginning Sept. 7 with three daily roundtrips between LaGuardia and Nashville, four daily flights between LaGuardia and St. Louis, and one daily flight between Kennedy and San Antonio.
Delta in September also will increase daily service on existing routes between LaGuardia and Norfolk, Va.; Richmond, Va.; and Kansas City. There will be increased service from Kennedy to Cleveland, Charlotte, Baltimore, Richmond, Montreal and Toronto.
Each new domestic route will have two-class service on 76-seat Embraer 175 jets (Nashville and St. Louis) or 124-seat Airbus A319 aircraft (San Antonio). Expanded domestic/Canada service will be operated with a mix of one- and two-class regional jets.
Delta previously announced the expansion of its Delta Shuttle to include service to Chicago O'Hare, beginning June 14, replacing flights between LaGuardia and Chicago Midway.