Federal prosecutors have asked a judge to cut nearly all of a potential $562 million fine against Pacific Gas & Electric Co. in a criminal case alleging pipeline safety violations before a deadly explosion in the San Francisco Bay Area.

The U.S. Attorney's Office made the request Tuesday in a court filing.

Under the proposal, PG&E would face a maximum fine of $6 million if convicted of obstructing investigators in the wake of the 2010 blast in the city of San Bruno and 11 pipeline safety violations.

The government did not provide an explanation in the filing for its request to lower the penalty.

Abraham Simmons, a spokesman for the U.S. Attorney's Office in San Francisco, said the office would have no comment.