A draft interim report from Ethiopian crash investigators circulated to US government agencies concludes the March 2019 crash of a Boeing Co 737 MAX was caused by the plane's design, two people briefed on the matter said Friday.

Unlike most interim reports, this one includes a probable cause determination, conclusions and recommendations, which are typically not made until a final report is issued.

The US National Transportation Safety Board has been given a chance to lodge concerns or propose changes, the people said, declining to be identified because the report is not yet public.

NTSB spokesperson Eric Weiss confirmed the agency had received the draft interim report, but declined to comment on whether the agency would suggest any changes. Boeing on Friday declined to comment to Reuters about the report.

According to Bloomberg News, which first reported the contents of the interim draft, the conclusions say little or nothing about the performance of Ethiopian Airlines or its flight crew and that has raised concern with some participants in the investigation.

The Ethiopian interim report contrasts with a final report into the Lion Air crash released last October by Indonesia which faulted Boeing's design of cockpit software on the 737 MAX but also cited errors by the airline's workers and crew.

Ethiopian Airlines flight 302 crashed in an open field six minutes after take-off from Addis Ababa, the Ethiopian capital, killing 157 passengers and crew. The Boeing 737 MAX has been grounded worldwide for nearly a year after the two fatal crashes.

Under rules overseen by the United Nations' Montreal-based aviation agency, ICAO, Ethiopia should publish a final report by the first anniversary of the crash on March 10 but now looks set to release an interim report with elements that would normally be included in the final report.

Ethiopian Airlines did not respond to a request for comment. Ethiopia's Transport Ministry could not immediately be reached for comment.

A preliminary accident report by the Ethiopian Civil Aviation Authority released in April last year said faulty sensor readings and multiple automatic commands to push down the nose of a Boeing plane contributed to the fatal crash and left the crew struggling to regain control.

The US House Transportation Committee on Friday released preliminary investigative findings into the two crashes which faulted the Federal Aviation Administration's approval of the plane and Boeing's design failures, saying the 737 MAX flights were "doomed".