In a ruling believed to be the first of its kind, a San Francisco judge has decided that all California drinkers of mineral water can share any rebates awarded in a pending lawsuit against the Perrier company. Superior Court Judge Raymond Williamson Jr. signed the class-action order. It marks the first time in California that a group of consumers has been allowed to be part of an antitrust lawsuit without being represented by a government agency, said attorney Patricia Sturdevant, who represented consumers. The lawsuit charges Perrier with price fixing and conspiracy to eliminate competition when it bought Calistoga mineral water in 1982. The Northern California company had been Perrier’s chief competitor. Perrier, a French company, and Great Waters of France, its distributor in the United States, raised the price of mineral water in California by at least 20 cents a bottle after Calistoga was purchased, according to the suit.