May 23 (GMM) Williams could switch to Mercedes power, Germany's Auto Motor und Sport is reporting.

Currently, the British team is powered by customer Renault engines, but the French marque is reportedly charging EUR 5 million more than its next most-affordable competitor for the turbo V6 units of 2014.

Pastor Maldonado, Williams FW35
Pastor Maldonado, Williams FW35

Photo by: XPB Images

"Williams could change," said correspondent Michael Schmidt, "because the contract is expiring." Caterham is reportedly also concerned about the high quoted price of the 2014 Renault.

Even more engine changes are afoot.

An announcement about Toro Rosso's switch from Ferrari to Renault is imminent, and Ferrari has already found a replacement -- Marussia.

"Announcement soon," said Schmidt.

Meanwhile, a rumour in the Monaco paddock is that Honda could fast-forward its return to Formula One from 2015 to 2014.

"Right now this is no more than a rumour," said Schmidt.

But there is great concern at Mercedes about 2014; when McLaren will use Mercedes engines, whilst 2015 partner Honda is at the very same time preparing its V6 design for the following season.

Mercedes chairman Niki Lauda said: "We will give McLaren only the information about our engine that they desperately need."