ExxonMobil yesterday tried to persuade the US Supreme Court it should not have to pay $2.5bn in punitive damages to victims of the 1989 Exxon Valdez oil spill, the largest such award in US history. The justices are being asked to bring closure to the lengthy legal dispute. The US business community is hoping that they will use the case, which involves a tanker crash that released 11m gallons of oil into Alaska's Prince William Sound, to discourage large punitive damage awards.