WASHINGTON (Reuters) - The Federal Aviation Administration said late on Wednesday it is forming an international team to review the safety of the now-grounded Boeing 737 MAX that will be headed by a formal top U.S. safety official.

FILE PHOTO: A wing of the Boeing 737 MAX is pictured during a media tour of the Boeing 737 MAX at the Boeing plant in Renton, Washington December 7, 2015. REUTERS/Matt Mills McKnight

The FAA said it is establishing a Joint Authorities Technical Review “to ensure the safety of the Boeing 737 MAX” and scrutinize an anti-stall software that’s been questioned in two fatal crashes since October.

The review will be chaired by former National Transportation Safety Board chairman Christopher Hart “and comprised of a team of experts from the FAA, NASA, and international aviation authorities.”

The FAA did not immediately disclose who was taking part but a Canadian government spokeswoman said Canada would join.

More than 300 Boeing 737 MAX jets have been grounded worldwide after two crashes - in Indonesia in October and in Ethiopia last month - killed nearly 350 people.

The FAA said the group “will conduct a comprehensive review of the certification of the automated flight control system on the Boeing 737 MAX aircraft” and “evaluate aspects of the 737 MAX automated flight control system, including its design and pilots’ interaction with the system, to determine its compliance with all applicable regulations and to identify future enhancements that might be needed.”

An FAA official said the review was independent of the agency’s timetable for deciding when to allow the 737 MAX back into service.

A Boeing spokesman said the company looked forward to working with the panel: “Safety is our top priority when we design, build, deliver and maintain Boeing aircraft.”

The review comes two days after the FAA and Boeing signaled the planes may be grounded for longer than previously thought.

Boeing said last week that it was reprogramming software on its 737 MAX passenger jet to prevent erroneous data from triggering an anti-stall system that is under mounting scrutiny following the two deadly nose-down crashes.

The world’s largest planemaker said the anti-stall system, which is believed to have repeatedly forced the nose lower in the Indonesia accident, would only do so one time after sensing a problem, giving pilots more control. Boeing said on Monday it will submit the software upgrade to the FAA in the “coming weeks.”

On Tuesday, the U.S. Senate Commerce Committee said it was investigating claims by a number of whistleblowers that aviation safety inspectors, including some who worked to evaluate the now-grounded Boeing 737 MAX, were not properly trained or certified.

Federal prosecutors aided by the FBI, the Transportation Department inspector general’s office and a blue ribbon panel to be named by Transportation Secretary Elaine Chao are also reviewing the plane’s certification.

The FAA has for decades delegated some certification duties to Boeing and other manufacturers.

Representative Peter DeFazio, who chairs the House Transportation and Infrastructure Committee, and Representative Rick Larsen praised the new review.

“Given the many serious questions surrounding the Boeing 737 MAX and the FAA’s certification process, it has become abundantly clear that an independent body must be able to review every step of the process and help restore public confidence ... well before the MAX is allowed to be restored to service,” DeFazio said in a statement.