Foreign Minister Guido Westerwelle offered on Monday to mend any dent in Germany's relationship with Britain after a divisive European Union summit earlier this month and said a strong British financial sector was in Europe's common interest.

For Germany, the United Kingdom is an indispensable partner in the European Union, Westerwelle told reporters at a joint press conference in London with British Foreign Secretary William Hague.

We should stay united, we should stay shoulder by shoulder and we should build bridges between us after the latest summit.. This is my offer and my gesture.

Britain was the sole country that did not sign up to an EU agreement aimed at resolving the euro zone debt crisis, raising speculation that Britain could become isolated from European decision making which could put the UK financial sector at risk.

There is no hidden agenda against the City of London. We think it is in our common interests, it is in our mutual interests, to have a strong segment of financial service here in the city of London, Westerwelle said.

(Reporting by Mohammed Abbas)