WASHINGTON (Reuters) -Families of some of the 346 people killed in two fatal Boeing 737 MAX crashes plan to object to a tentative nonprosecution agreement between the planemaker and the U.S. Justice Department, a lawyer said on Saturday.

The Justice Department outlined the tentative deal in a more than two-hour meeting with families on Friday and said in a court filing on Saturday that they would have until Thursday to file written objections.

Paul Cassell, a lawyer for the families, said they would object "to any deal along the lines described by DOJ yesterday, because it fails to hold Boeing accountable for the 'deadliest corporate crime in U.S. history,'" citing the prior comments of U.S. District Judge Reed O'Connor.

The Justice Department said in its filing "it has not decided whether to enter into the agreement or to proceed to trial, and would not make the decision until after finishing conferring with the families."

The agreement would forestall a June 23 trial the planemaker faces on a fraud charge it misled U.S. regulators about a crucial flight control system on the 737 MAX, its best-selling jet.

The agreement would allow Boeing to avoid being branded a convicted felon and would be a blow to families who lost relatives in the crashes and had pressed prosecutors to take the U.S. planemaker to trial.

"The new deal is a step backward from last summer, when Boeing was going to plead guilty," Cassell added. "Under the new arrangement, they don't plead guilty."

Boeing declined to comment.

Boeing agreed in July to plead guilty to a criminal fraud conspiracy charge after the two fatal 737 MAX crashes in Indonesia and Ethiopia, spanning 2018 and 2019, and to pay a fine of up to $487.2 million.

Boeing and DOJ officials have not yet exchanged papers to negotiate final details of any nonprosecution agreement, the department said Saturday.

The Justice Department told families on Friday that Boeing would be asked to pay an additional $444.5 million into a crash victims' fund that would be divided evenly per crash victim, lawyers for the families said, on top of $500 million Boeing paid in 2021.

Boeing has faced enhanced scrutiny from the Federal Aviation Administration since January 2024, when a new MAX 9 missing four key bolts suffered a mid-air emergency losing a door plug. The FAA has capped production at 38 planes per month.