Boeing has agreed to plead guilty to a U.S. criminal fraud charge related to the crashes of two 737 Max jetliners, angering the families of the hundreds of passengers killed who had wanted the case to go to trial.

The Guardian reports that federal prosecutors had found that the American planemaker was in violation of a 2021 agreement struck after the crashes, which had protected it from prosecution for more than three years.

On June 30, the U.S. Department of Justice (DoJ) gave Boeing the choice of entering a guilty plea and paying a fine as part of its sentence or facing a trial on the felony criminal charge of conspiracy to defraud the U.S. over the crashes, which claimed 346 lives.

Under the new plea deal, which must receive the approval of a federal judge to take effect, Boeing will pay a $243.6m fine, according to a DoJ document filed in federal court in Texas.

The company has also agreed to invest at least $455m over the next three years to strengthen its safety and compliance programs, the department said.

Relatives of the Max crash victims were briefed on the agreement a week ago and labelled it a “sweetheart plea deal” that spared Boeing the scrutiny of a criminal trial.