Manchester City have made a £15 million bid for West Ham United midfielder Valon Behrami.

The Telegraph says the offer for the Swiss international will test the resolve of West Ham's new owners, David Sullivan and David Gold, to hold on to one of their star players. However the co-chairmen may decide that, by cashing in on the 24 year-old, they may be able to provide extra funds to bolster Gianfranco Zola's relegation-threatened squad.

West Ham have so far made it clear that Behrami, who was signed from Lazio for £5 million, on a five-year deal in July 2008, is not for sale.