European shares extended gains to fresh six-month highs in afternoon trade on Wednesday after Greece's Conservative Party said its leader had sent a letter of commitment to austerity measures to the Eurogroup.

The party also said in a statement that it remained committed to targets and policies of the bailout, in case it won elections.

At 12:37 p.m., the FTSEurofirst 300 <.FTEU3> index of top European shares was 1 percent higher at 1,080.02 points after rising to a six-month high of 1,080.27.

It looks like we are almost there (on Greece). There is a bit of a sigh of relief and the market is taking its lead from it, said Chris Theis, head of institutional sales at Merchant Securities.

(Reporting by Francesco Canepa and Atul Prakash)