NEW YORK (AP) — Delta Air Lines said Friday it will close its regional carrier Comair at the end of September as it switches more of its flying to bigger jets.

Delta, which is based in Atlanta, has about 350 regional jets and plans to reduce that to 125 within two years. Operating regional carriers has become more expensive while customers have been demanding roomier planes.

Comair represents only about 1 percent of Delta's flying, so the closure won't result in significant changes to Delta's network. Delta also said it won't result in fewer flights out of Comair's base at Cincinnati/Northern Kentucky International Airport.

Comair was founded in 1977. It started operating as Delta Connection in 1984. The regional airline had about 290 flights a day and has 1,700 employees as of March, according to its website.

Before entering bankruptcy in September 2005, Comair had more than 7,000 employees and 1,160 flights.