Lance Armstrong moved level with Fabian Cancellara at the head of the overall standings after helping Astana to a team time-trial success on stage four of the Tour de France.

Cancellara, of Saxo Bank, retains the yellow jersey going into tomorrow's fifth stage but Armstrong, the seven-time winner of the Tour, was able to wipe out a 40-second deficit on the roads of Montpellier.

Astana posted a time of 46 minutes and 29 seconds to win the 39km stage, with Garmin-Slipstream finishing second 18 seconds back and Saxo Bank third, a further 22 seconds behind.

Alberto Contador, Armstrong's team-mate, moves into third place in the overall standings while Andreas Kloden and Levi Leipheimer, who also ride for Astana, make up the top five.

Britain's Bradley Wiggins and David Millar, who both ride for Garmin-Slipstream, finished the day in sixth and tenth place respectively. Mark Cavendish, the winner of the second and third stages, retains the green jersey.