Hamilton back on track after early hiccup

The young Briton, who was confirmed as Fernando Alonso's teammate on Friday, stopped at the first corner of the Circuit de Catalunya with a suspected mechanical problem.

The issue was quickly rectified, however, and Hamilton has resumed running.

Hamilton is currently running alongside Pedro de la Rosa, but there are mounting suggestions that former world champion Mika Hakkinen may test for the team this week.

Eight teams have joined the opening day of winter testing. As well as McLaren, Renault are represented by Nelson Piquet Jr. and Heikki Kovalainen, Ferrari have Luca Badoer and Felipe Massa while Honda are using Rubens Barrichello and James Rossiter.

Honda's Jenson Button, who has been forced to skip the test so as not to aggravate his injured ribs, is still present to oversee proceedings.

Mark Webber is getting his first taste of Red Bull Racing machinery alongside David Coulthard, while Super Aguri's Anthony Davidson is making his first appearance as their race driver. Williams have only Alex Wurz on track.

BMW-Sauber are using their race drivers Nick Heidfeld and Robert Kubica, as are Scuderia Toro Rosso who have Scott Speed and Vitantonio Liuzzi on board.