Robert Kubica will be free to sign with another formula one team unless Renault guarantees his seat in the coming weeks, according to a report on Friday in Spain's Diario AS.

The 24-year-old Pole has signed a contract to race with the French squad in 2010, but Renault is contemplating its commitment to formula one and is set to announce its plans before the end of the year.

AS said that if Kubica is available, Mercedes GP would be interested in signing the former BMW-Sauber driver to be Nico Rosberg's teammate.

The report cited "sources" in claiming that if Renault does not commit to F1 "in the coming weeks" Kubica will be "automatically released" from his contract.

Renault announced on Friday that, alongside Bertrand Baguette and Lucas di Grassi, the 26-year-old Dutch-born Chinese Ho-Pin Tung will test the R29 at next week's young driver session at Jerez.

Tung has previously tested for Williams and this year raced in the Superleague Formula series.

"This young driver test is the perfect opportunity for us to assess rising stars such as Bertrand, Ho-Pin and Lucas," said team boss Bob Bell.



Source: GMM