Mitsubishi Heavy Industries Ltd. agreed to buy Bombardier Inc.'s CRJ regional-jet program for $550 million, extending a push into commercial aircraft and setting up a rivalry with Embraer SA and Boeing Co.

The Japanese manufacturer will also assume liabilities of about $200 million and take over Bombardier's interest in a regional-jet securitization program, which is valued at about $180 million, according to a statement by the companies Tuesday.

The deal, expected to close in the first half of next year, gives Mitsubishi a worldwide maintenance and support operation in addition to an aging line of short-haul jets. That will bolster the company's ability to market its SpaceJet regional aircraft, the first airliner built in Japan since the 1960s.

For Bombardier, the transaction caps a strategic overhaul in which Chief Executive Officer Alain Bellemare is largely exiting the commercial airplane business to focus on making business aircraft and trains. The company last year handed control of its C Series jetliner program to Airbus SE, which renamed the plane the A220.

Mitsubishi will face off with Embraer in the market for small planes. The Brazilian manufacturer is in the process of combining its commercial jet business into a joint venture with Boeing.

Bombardier was briefly suspended ahead of the market open in Toronto. The announcement was made after the markets closed in Tokyo.