MONT SAINT MICHEL (AFP) - Tour de France leader Chris Froome tightened his grip on the yellow jersey after finishing second on the 11th stage time trial won by world champion Tony Martin on Wednesday.

Martin had set the early pace for a windswept 33km course from Avranches to Mont Saint Michel in 36min 29sec, but had a nervous wait as Froome threatened to upset his hopes of victory.

In the end Team Sky's leader Froome came home in second place at 12secs adrift but finished more than two minutes ahead of principal rival, two-time champion Alberto Contador of Spain.