(JTA) -- Casino and hotel magnate Sheldon Adelson reportedly has given a “substantial” new donation to a group supporting Newt Gingrich for the Republican presidential nomination.

Adelson gave the donation to Winning Our Future, an independent committee, or Super PAC, that is run by former Gingrich associates, Politico reported Tuesday, one week ahead of the Super Tuesday primary vote in 10 states. Adelson and his wife already have given $11 million to the PAC.

The new contribution, which came in a few days ago, is comparable to previous ones, Reuters reported, citing a source familiar with the donation.

CNN and CBS reported last week that Adelson would give $10 million more to the group.

Gingrich has been slipping in the GOP race for the presidential nomination.

Super PACs can raise unlimited sums from corporations, unions and other groups, as well as individuals, and indirectly support a political candidate. They cannot by law coordinate with the candidate's official campaign.

Adelson, chairman and CEO of the Las Vegas Sands Corp., is worth more than $21 billion, according to Forbes magazine. He is a major giver to Birthright Israel, which provides free 10-day trips to Israel for Jews aged 18 to 26.