The U.S. Supreme Court struck down the federal law that bars gambling on individual sporting events in most of the country, in a ruling likely to unleash a race among the states to attract billions of dollars in legal wagers.

Ruling in a New Jersey case, the court said the 1992 law unconstitutionally forced states to maintain laws that ban gambling. Nevada is the only state where single-game wagering is now legal.

Sports gambling could begin in a matter of weeks in casinos and racetracks in New Jersey, which instigated the legal fight by repealing its gambling prohibition. Mississippi, Pennsylvania, New York, Delaware and West Virginia could follow soon, and the number of states might reach double digits by the end of the year.

Casino stocks, including Scientific Games Corp., Boyd Gaming Corp., MGM Resorts International and Caesars Entertainment Corp., jumped after the decision. Other companies such as online gaming giant The Stars Group Inc. and International Speedway Corp. also climbed.

The vote was 6-3 to strike down the entirety of the federal prohibition.

Americans place $150 billion a year in illegal sports bets, according to the casino-backed American Gaming Association. The research firm Eilers & Krejcik Gaming puts the number at $50 billion to $60 billion, not counting bets among friends.

The ruling starts a new era for the largest sports leagues, which fought New Jersey in court even while moving toward embracing legalized sports wagering. In January, a National Basketball Association executive told New York lawmakers the leagues should get 1 percent of all bets. The NBA says it would prefer a new federal law to set nationwide standards.

-Bloomberg News