VANCOUVER, Feb. 14 (Reuters) – Jazz Air Income Fund said it had signed a letter of intent to buy 15 turboprop aircraft from Bombardier Inc., with an option to buy another 15, as the Canadian regional airline operator updates its fleet.

The Q400 NextGen aircraft will seat 74 passengers and deliveries are scheduled to begin in May 2011, Jazz said.

No financial terms were released.

Bombardier, the world's No. 3 civil aircraft maker, said it would not put a dollar figure on the deal until it was firmed up.

''We're working to finalize a firm purchase agreement on the sale of NextGen Q400 aircraft,'' said John Arnone, a Bombardier spokesman.

The list price on a Q400 turboprop is around $29 million.

Jazz, a regional carrier for Air Canada, already flies Bombardier-built Dash 8 turboprops and CRJ regional jets.

The new planes will replace 15 of Jazz's 50-seat regional jets.

''This aircraft (the Q400 NextGen) offers superior passenger comfort, fuel efficiency and improved environmental performance,'' Jazz Chief Executive Joseph Randell said in a statement. He said the Q400's operating costs are ''among the lowest of any regional aircraft.''