A US judge says energy giant BP faces a maximum fine of $US13.7 billion ($A14.82 billion) for the 2010 Gulf of Mexico oil spill, a sum reduced by several billion dollars.

A fine of up to $US18 billion had originally been set as a possible penalty, based on government estimates that 4.19 million barrels of oil were released into the Gulf of Mexico. But US federal court judge Carl Barbier said on Thursday in New Orleans the penalty should be based…