Mesa Airlines and Bombardier have reached an agreement in principle for seven Bombardier CRJ900 NextGen aircraft with deliveries through the fourth quarter.

“We are delighted to have the opportunity to order brand new aircraft from Bombardier and place them into service under a long-term capacity purchase agreement,” says Jonathan Ornstein, chairman and chief executive of the Phoenix-based regional carrier, in a statement. “Building on our core business with American and United, Mesa is now the fastest growing regional airline in the country.”

Mesa will operate the aircraft under a long-term agreement with a mainline carrier partner, it says.

The airline operates 57 CRJ900s, including 10 that it recently bought used from Alitalia, under contracts with American Airlines.

Mesa’s order is valued at about $321 million at list prices if it is finalised, Flightglobal estimates. The deal includes an undisclosed number of options.

The CRJ900s will be delivered through October, when the regional carrier’s fleet will include 115 aircraft.

Bombardier declines to comment.

Source: Cirium Dashboard