Billionaire Sheldon Adelson is willing to bet $10 billion that his Las Vegas Sands will become the leader in casino gambling in Japan, an offer he says his competitors can't match.

What remains to be seen is whether one of the world's last great untapped gaming markets is willing to bet on him.

For months, the chief executive of the world's largest casino operator by market value has insisted he's the person to beat in Japan as it moves closer to legalizing casinos, with the Diet expected to start deliberating an initial bill in May.