Business Express, a commuter airline affiliated with Delta Airlines, will launch service between Baltimore and New York next week and also will introduce jets on its existing service to Boston.

Westport, Conn.-based Business Express will offer four round-trip flights a day between Baltimore-Washington International Airport and Kennedy International Airport in New York.

Monday, the airline will begin using jets on one of its five daily flights to Boston. In April, the jet service will be expanded to two of the five flights, and in May, all five flights will be jet service. The jets seat 80 passengers.

Baltimore-Boston is the second-busiest route out of BWI, according to the Maryland Aviation Administration. USAir has seven non-stop jet flights a day to Boston, and Northwest Airlink has two commuter flights a day.

Northwest Airlink extended its Boston-Baltimore service Feb. 12 to include Norfolk, Va.

America West is also revising its service from BWI by beginning jet service tomorrow to Columbus, Ohio. America West will be the only airline providing non-stop service on that route.

America West has had three jet flights daily out of BWI -- two non-stops to Phoenix and one to Las Vegas.

Under the new schedule, America West will continue three flights a day out of Baltimore, but two of them will be to Columbus.

One of the Columbus flights will continue to Las Vegas, the other to Florida. The airline will retain one non-stop flight a day from Baltimore to Phoenix.