Feb.5 (GMM) Williams team co-owner Patrick Head has acknowledged that the Grove squad stands to lose Nico Rosberg if the young German is not given a front-running car to race.

Rosberg, 22, recently inked a new contract to keep him at the Toyota-powered outfit until the end of next year. He warned that if he is not firmly a front runner by then, he will search for an alternative employer.

McLaren-Mercedes was interested in buying Rosberg from Williams for the 2008 season, but Head and the team's chief Sir Frank Williams remained firm that their climb back to the to top requires a driver of Nico's calibre.

Head acknowledges the McLaren speculation but insists that, "internally, it was always clear that we would not be letting him go".

The British team veteran also admits that Rosberg will not be forever content to collect F1's 'best of the rest' plaudits.

"He is very determined to be a successful driver," Head said, "and we are equally committed to return to being a successful team."

Oxfordshire based Williams is among F1's historically most successful teams, but since 1997 has not won a title. Since 2004, Williams has not won a race.

Head said of Rosberg: "We need to arrange a better car for him.

"If we do not manage to do that, the speculation will surely come back -- and then it is possible that the story will play out differently," he told the Swiss specialist publication Motorsport Aktuell.