Calpers, the largest US pension fund with $162bn (€131bn) in assets under management whose aggressive stance on corporate governance polarised opinion in the US investment industry, is to change its policy.

A spokesman for Calpers said on Tuesday: "I think we are going to be more flexible in our approach and look at other ways to approach these problems. We are going to think more strategically and be more focused as opposed to the broad approach we took as far as voting our proxies on the audit issue."