MONTREAL - U.S. Federal Aviation Administration (FAA) representatives told members of the United Nations' aviation agency they expect approval of Boeing Co's 737 MAX jets to fly in the United States as early as late June, three people with knowledge of the matter said, although there is no firm timetable for the move.

FAA and Boeing representatives briefed members of the International Civil Aviation Organization's (ICAO) governing council in Montreal Thursday on efforts to return the plane to service.

The three people spoke on condition of anonymity to discuss the private briefing.

Grounded in March

The MAX was grounded worldwide in March following two crashes involving the model that killed a combined 346 people.

FAA officials who briefed the council said they expected the grounding to be lifted in the United States as early as late June, but it was not clear when other countries would clear the flights, two of the sources said.

Canada and Europe said Wednesday they would bring back the grounded aircraft on their own terms.

The FAA declined to comment Thursday, referring to acting administrator Dan Elwell's statement Wednesday that he does not have a timetable for making a decision.

"It's taking as long as it takes to be right," he said. "I'm not tied to a timetable."

Boeing did not immediately respond to a request for comment. Its shares pared earlier losses to close down 0.6% at $350.55.

UN agency clout

The ICAO gathering comes as the FAA is meeting with international air regulators in Texas to discuss what steps are needed to return the 737 MAX to service, while the International Air Transport Association (IATA) is hosting MAX airline operators from across the world in Montreal.

Montreal-based ICAO cannot impose binding rules on governments, but wields clout through its safety and security standards, which are approved by its 193 member states.