Fleet Management Ltd. was the ship operator, in charge of training and supervising the crew, when the Cosco Busan hit a fender of the Bay Bridge on Nov. 7, 2007, and spilled 53,000 gallons of oil.
The company has told U.S. District Judge Susan Illston that it wants to plead guilty to two misdemeanor counts in a 2008 indictment. The charges are polluting the Bay and killing migratory birds.
But prosecutors contend that if the company wishes to plead guilty, it must do so to a revised indictment issued on May 26 that specifies the loss caused by the spill was at least $20 million.
Under prosecutors' interpretation of sentencing laws, the company could be subject to a fine of double that amount, or up to $40 million.
The actual fine, if any, would be determined by the judge. The company contends it was unfair of prosecutors to obtain a revised indictment at the last minute.
Fleet Management attorneys have maintained in court filings that the maximum fine under the previous indictment would be $400,000 and that a huge fine could "potentially cripple Fleet financially."
Justice Department prosecutors have replied that "there is nothing improper" with their obtaining a revised indictment from a grand jury.
The prosecutors have said the $20 million figure is based on the fact that Fleet Management has acknowledged paying more than $21 million to fisherman, local businesses and government agencies for damage caused by the spill.
Total costs of the spill, including environmental cleanup costs, are estimated at more than $70 million.
Pilot John Cota pleaded guilty to the same two misdemeanor charges in March and is awaiting sentencing.