The Government's plans to raise £750m from National Lottery games to part-fund the 2012 London Olympics are "at risk" if the lotto licence changes hands in 2009, the industry's regulator admitted yesterday.

The news came as the National Lottery Commission announced plans to extend the present seven-year licence to 10 years from 2009, when Camelot's term expires.

Camelot has the task of raising £750m of the £2.5billion Olympic budget from lotto games.

The bulk of this figure -£500m - will be raised after the Beijing Games in 2008 when Camelot is hoping that Olympic fever will fire punters' hunger for London in 2012.

However, Robert Foster, the National Lottery commissioner, admitted that there was a risk that the fund-raising could be hit by the licence changing hands in 2009.

He said: "There has to be an element of risk if there was a change. But there is always risk in anything you do."

So far, £2.7m has been raised for the Olympics from two Go for Gold scratch card games. A third game is due to be launched in February.

One senior Camelot source said: "If you look at international examples, whenever there has been a change in licence holder, sales have gone down."

The National Lottery Commission's statement of main principles, which is published today, stipulates a one-stage bidding process for the 10-year licence to cap bidding costs at around £6m for each consortium.

It says that "ultimately the licence will be awarded to the bidder that is able to support the greatest forecast returns to good causes while demonstrating that they can meet other required standards".