Oct.25 (GMM) Sir Frank Williams has advised his McLaren counterpart Ron Dennis against even trying to put Nico Rosberg in a Mercedes-powered single seater for 2008.



"Ron Dennis does not even have to try," the Grove based team's co-owner and principal told the German magazine Auto Motor und Sport.



"Nico is not for sale."



Williams' latest comments follow Mercedes competition director Norbert Haug's revelation that McLaren chiefs are now knuckling down to determine the team's 2008 driver lineup for 2008.



The openly uncomfortable Fernando Alonso has an ongoing contract, but Haug told Bild-Zeitung on Thursday that the team is currently "discussing internally" the driver question.



And the German told RTL in Brazil last weekend: "Nico is a very impressive driver, who has in the last two years at Williams learned an awful lot."



Rosberg, meanwhile, was not entertaining the McLaren rumours at Interlagos. "I am happy where I am," the 22-year-old insisted.



"Here I have the opportunity to grow with a great team."



He finished a career best fourth last Sunday, and commented: "I am super happy with how this season has ended.



"Our goal for next year must be to move even closer to BMW."