Allen & Overy is abolishing its mandatory partner retirement age of 60 as a growing number of major London law firms move away from compulsory retirement dates for partners in the U.K. The City giant's move comes as research by Legal Week found that SJ Berwin, Nabarro and Holman Fenwick Willan are also currently reviewing their policies in the wake of legislative changes which have phased out default retirement ages for U.K. employees. Three other major firms - Ashurst, Hogan Lovells and Linklaters - had already removed default retirement ages from their partnership deeds in light of the changes to U.K. employment law that were originally floated in 2006. The findings are based on responses from 25 of the 30 largest U.K. firms by revenue and follow the introduction of new retirement laws in October 2011 that prevent employers from compulsorily retiring employees at 65 without full justification...