Dec 1 (Reuters) - A new U.S. rugby union sevens league will launch next October, which organisers said on Wednesday would pit 12 top international teams against four new U.S. franchises, with sides playing to win their share of $1 million prize money. A newly-formed U.S. company, The Rugby Football League, said the U.S. Rugby Sevens Major League would start in Las Vegas. Fans at home and at the matches will have access to live betting markets, in-running stats, insights and expert advice throughout each game, the organisers said. From 2023, the RFL, which is not affiliated with the governing body of professional rugby league in England with the same name, said it would hold up to 17 tournaments in major U.S. cities and will feature up to 16 U.S. team franchises playing with top international teams.