The US Justice Department on Tuesday said Boeing can be prosecuted for two subsequent 737 Max crashes that killed 346 people approximately five years ago.
Boeing breached obligations under an agreement that had shielded it against legal proceedings for the accidents, department officials said in a letter to a federal court in Texas.
Boeing told AFP "we believe that we have honored the terms of that agreement" and said that it plans to defend itself.
US officials said in their letter that Boeing breached its obligations under a deferred prosecution agreement (DFA) by "failing to design, implement, and enforce a compliance and ethics program to prevent and detect violations of the US fraud laws throughout its operations."
Such a breach would mean Boeing can be prosecuted for any violation of federal law related to the crashes, according to US justice officials.
The government is evaluating how to proceed in the matter and has directed Boeing to respond by June 13.
US officials also plan to confer with families of people who died in the Lion Air Flight 610 and Ethiopian Airlines Flight 302 crashes.
"This is a positive first step, and for the families, a long time coming," said attorney Paul Cassell, who represents crash victim families.
Cassell called for further action from the Department of Justice and added he would seek details regarding a "satisfactory remedy" to Boeing's wrongdoing.
In March of 2019, a Boeing 737 MAX 8 operated by Ethiopian Airlines crashed southeast of Addis Ababa, killing the 157 people on board.
It was the second accident in five months for a 737 MAX aircraft, a product line meant to replace the 737 NG.
The first crash, involving a MAX 8 operated by Lion Air, occurred in October of the prior year in Indonesia's Java Sea and left 189 people dead.
Both aircraft crashed shortly after takeoff, with investigations later pointing to trouble with the automated flight system.
The aircraft were temporarily grounded or banned from airspace around the world.
"We will engage with the Department with the utmost transparency, as we have throughout the entire term of the agreement," Boeing said in a statement to AFP.
It said this also included "response to their questions following the Alaska Airlines 1282 accident."
The dramatic mid-flight blowout on January 5 of a fuselage panel on an Alaska Airlines plane precipitated the departures of a series of top Boeing officials -- including CEO Dave Calhoun, who is set to step down at year's end.
It also resulted in reduced production of the 737 MAX.
The US Federal Aviation Administration was sharply criticized after the crashes of two Boeing 737 MAX planes in 2018 and 2019.
But as Boeing faces multiple inquiries and audits in the United States and abroad, it has repeatedly assured critics that it is working "with full transparency and under the oversight" of FAA regulators.
The DPA required Boeing to pay $2.5 billion in fines and restitution in exchange for immunity from criminal prosecution for charges it defrauded the government during the certification of the MAX.
A federal judge in Texas early last year rejected a challenge by relatives of Boeing 737 MAX crash victims to the aviation giant's US criminal settlement, ruling against ordering changes to the controversial January 2021 DPA.
The families have argued that Boeing's role in what they have called the "deadliest corporate crime" in US history merits criminal conviction of the company and top brass.
