Business leaders, including top executives at Lawson Inc. and Suntory Holdings Ltd., are joining forces to back the legalization of casinos in Japan, a proposal that could open up what is estimated to be the world's second- largest gaming market.

Lawson Chief Executive Officer Takeshi Niinami and Suntory Executive Vice President Shingo Torii are among corporate and academic leaders forming a group to support a legalization bill introduced by lawmakers, said Hiroshi Mizohata, a former head of the Japan Tourism Agency, who will also be a member.

Niinami, who heads the nation's second-largest convenience store chain, and Torii, of the country's third-biggest brewer, expect to add momentum behind a bill submitted last month by lawmakers from the ruling Liberal Democratic Party to legalize resorts that combine casinos with hotels and convention centers. Casino operators from MGM Resorts International to Wynn Resorts Ltd. plan to spend billions of dollars to build gambling resorts here if they are legalized, the companies have said.