Fleet Management Ltd. was the operator of the Cosco Busan, with responsibility for training and supervising the crew, at the time the ship spilled 53,000 gallons of oil into the San Francisco Bay on Nov. 7, 2007.
The spill occurred after the container ship hit a protective fender of the Bay Bridge in heavy fog.
The company has told U.S. District Judge Susan Illston it wants to plead guilty to two misdemeanor charges of polluting the Bay and killing migratory birds. Illston will hold a hearing on the request on June 19.
But in a new filing Monday, the company asked the judge to shield it from being subjected to up to $40 million in fines.
The company contends that federal prosecutors on May 26 - after Fleet Management offered to plead guilty - unfairly obtained a revised indictment that sets the loss caused by the spill at $20 million.
Under prosecutors' interpretation of sentencing laws, Fleet Management could be responsible for twice that amount, or $40 million, as a penalty for its guilty plea, according to the company.
The company says that under its own interpretation, the maximum fine for the two counts would be $400,000.
It asks Illston to allow it to plead guilty to the two counts in an earlier indictment that did not set a loss amount.
Company attorneys wrote that a multimillion-dollar penalty would be "a huge fine that would potentially cripple Fleet financially as well as fatally damage its reputation in the shipping community."
A representative of the U.S. attorney's office was not immediately available to comment on whether prosecutors are in fact seeking a fine of up to $40 million.
Prosecutors are due to file a written response with Illston by June 8.
Pilot John Cota pleaded guilty to the same two misdemeanor charges in March and is awaiting sentencing.