Viewers with an interest in F1 might have noticed that Renault appeared without branding from Spanish Telecommunications giant Telefonica during testing at Jerez this week.

Although Renault is yet to reveal its final 2007 race livery, Telefonica's absence suggests a split from the French manufacturer since other more minor sponsors were still present on the car.

Telefonica and/or its mobile phone arm Movistar were a major sponsor for many years in all three classes of the motorcycle world championships, but put its full backing behind Renault - or more precisely Spanish hero Fernando Alonso - for 2006 (middle picture). Its decision had been prompted by outrage that Dani Pedrosa, whose career it had supported from the start, would graduate to the premier MotoGP class wearing Repsol Honda rather than Movistar Honda colours.

However, reigning double F1 world champion Alonso has now left Renault for McLaren - which has a long term title sponsorship deal with Vodaphone - while Renault has hired rookie Heikki Kovalainen to replace Alonso alongside Italian Giancarlo Fisichella. That new line-up might not be attractive to Telefonica and the current lack of logos could confirm that the company will not be present in 2007.

So, assuming a split, where might Telefonica money go? The other leading F1 teams already have main sponsors in place, but there is one very major MotoGP team still unbranded for 2007 - the Factory Yamaha Team, formerly backed by Camel, which will field Colin Edwards and a certain Valentino Rossi.

With Michael Schumacher now retired, seven-times world champion Rossi is now - despite his 2006 title loss - arguably the most high-profile active motor-sportsman in the world... Telefonica must surely be tempted.