The average age of new partners at the top 10 City firms is now almost 35, as associates face a longer wait before being made up.
According to The Lawyer's research, the average age of partners made up this year is 34.7 years. Of the top 10 firms, those with the highest average age for new partners are Lovells and Clifford Chance, with averages of 37.2 years and 36 years respectively.
Most top 10 firms run a partnership track of six or seven years' post-qualification experience.
One partner at a top 10 firm, who was made up at the age of 30, said: "In my day, if you weren't made up by the age of 33 then you'd never be made up."
The overall number of promotions has remained virtually static over the last three years. This year firms made up 172 partners compared to 174 and 170 in 2004 and 2003 respectively.
Banking and finance lawyers made the greatest gains, with 25.5 per cent of total partner promotions. This was a marked increase on 2004 when 19 per cent were made up, and it was the only field where there was a significant discrepancy on last year, although both corporate and litigation dipped slightly.
The research also reveals that marginally more women partners were made up this year than last. In 2005 there were 39 new women partners (or 22.6 per cent), representing a marginal increase on last year's 22.2 per cent. Slaughter and May, which made up no female partners in 2003 and 2004, this year promoted two women out of a total six new partners.