The 737 MAX 8 was grounded by US on March 13 after several other countries had done so. (File)

The global aviation association IATA expects Boeing's troubled 737 MAX 8 plane to remain grounded for at least 10 to 12 more weeks, director general Alexandre de Juniac said Wednesday.

In March, an Ethiopian Airways Boeing 737 MAX 8 crashed killing all 157 people on board, less than five months after a similar disaster involving a Lion Air 737 MAX 8 that killed all 189 people on board that plane.

The 737 MAX 8 was grounded by US authorities on March 13 after several other countries had already done so.

Responding to a question about when the aircraft might fly again following two crashes, the head of the International Air Transport Association told a news conference: "Its difficult to say. What we understand from the regulator, at least 10 to 12 weeks will be the minimum delay."

The decision "is in the hands of the various regulators and agencies which are responsible for certification", he added.

De Juniac said a meeting was to be held "five to seven weeks from now" with airlines, regulators and aircraft manufacturers to assess "what has been done and what is still to be done to prepare a perfect re-entry to service of that aircraft".

Meanwhile, IATA did not have information on what sort of compensation might be expected as a result of the plane being grounded, he said, adding that the priority at present was to "restore the confidence in the certification process".

Several airlines have indicated they would seek compensation for the fact that they could not use the the 737 MAX 8 planes in their fleets.

According to Boeing, 371 of the aircraft were in service.

Prior to the crashes, airline regulators worldwide generally recognised certifications issued by their peer in the country where the aircraft was built, which in this case was the US Federal Aviation Administration.

Following the crashes however, the Seattle Times reported that the FAA had delegated part of the certification process for the plane to Boeing engineers.

Acting FAA Administrator Daniel Elwell said after a meeting on May 23 that his administration was more focused on making sure the 737 MAX 8 was safe than in drawing up a timetable for its return to service.