A Canadian company plans to sue the U.S. government under NAFTA, seeking $970 million in damages because California has banned MTBE, a methanol-based gasoline additive that is a key source of revenue for the company. California Gov. Gray Davis (D) in March announced that the state would phase out MTBE, which helps fuel burn more cleanly but is also linked to serious groundwater pollution. Methanex Corp., the world leader in methanol production, argues that the ban would dramatically harm its business, particularly if other states follow California’s lead.