Boeing's chief safety officer, Mike Delaney, entered the not-guilty plea on behalf of the planemaker. A not-guilty plea is standard in deferred prosecution agreements.

U.S. District Judge Reed O'Connor last week ordered Boeing to appear to be arraigned after he ruled that people killed in the two Boeing 737 MAX crashes are legally considered "crime victims."

The crashes in Indonesia and Ethiopia killed 346 people. They cost Boeing more than $20 billion, led to a 20-month grounding for the best-selling plane and prompted lawmakers to pass sweeping legislation reforming airplane certification.

The families want O'Connor to name an independent monitor to oversee Boeing's compliance; impose a standard condition that Boeing commit no new crimes; and disclose publicly as much as possible of the substance of Boeing's corporate compliance efforts adopted since 2021.

Boeing Chief Executive Dave Calhoun told CNBC Wednesday the planemaker did not object to the arraignment and expressed sympathy for the families.

The Justice Department in 2021 agreed to seek dismissal of the charge after the three-year agreement if Boeing complies with all terms. Boeing admitted in court documents that two of its technical pilots deceived U.S. regulators about a key flight control system linked to both fatal crashes.

Relatives of people killed were speaking Thursday at the arraignment. The relatives said in the filing that Boeing had "committed the deadliest corporate crime in U.S. history."

Boeing and the Justice Department oppose reopening the $2.5 billion agreement, which included $500 million in victim compensation, a $243.6 million fine and $1.7 billion in compensation to airlines.

Boeing in 2021 said it was accepting responsibility for compensating families of those killed in the crashes. Lawyers for the victims said Boeing admitted under the agreement "that the 737 MAX had an unsafe condition, and that it will not attempt to blame anyone else" for the crash.

(Reporting by Sheila Dang and David Shepardson; editing by Jonathan Oatis)

By Sheila Dang and David Shepardson