Frank Williams has revealed that in its quest to replace Fernando Alonso, McLaren made an offer of "majestic proportions" to lure Nico Rosberg to Woking.

"It was never a thought we entertained," Williams told reporters at a pre-season luncheon. "We had an offer, of majestic proportions, but it was never ever discussed.

"Why would we give away the crown jewels?" he continued. "Why bother improving the car by one second if we then give away half a second with the driver?"

Although aware that McLaren was searching for a new teammate for Lewis Hamilton, and much to the surprise of many within the paddock, in mid-December Rosberg signed a new deal with Williams, effectively keeping him at Grove until the end of 2009.

Williams admits that though he had the German hot-shot tied-up for 2008 he was concerned that a deal might be agreed for a future move.

"I was a little surprised he was happy to sign to stay," said the Englishman. "I feared he would go to McLaren and I was a bit surprised that he didn't. He could not have gone there this year, he had a fixed contract, but 2009 was going to be the worry. We had an option for 2009 but it was very tough terms, based on the constructors' championship."