The strong pound has affected the profits of some of the City's leading international law firms.

The Lawyer has learned that Clifford Chance has lost around 10 per cent of its profits because of the strong pound while Freshfields also confesses its profits would have been bigger without sterling's strength.

But the reverse has not stopped both firms from cashing in on a bumper year for the City with fee income rises of 10 to 20 per cent and overheads rising by less.

The figures come as, for the first time, monthly legal journal Commercial Lawyer has joined its rival Legal Business in producing a mixture of estimated and researched profit figures for the top 100 law firms.

Clifford Chance's profits have slipped from last year if the figures are to be believed, but a spokesman stressed that it was still number one for fee income, billing £310m.

However, sources close the firm say that the partners' aim is to achieve take-home profits on a par with Slaughter and May, where the partners on the biggest profit share take £700,000 and average profits per partner are more than £500,000.

Clifford Chance has suffered particularly because of its many large international offices.

Like Freshfields, which has also been adversely hit by the strong pound, the firm bills in local currencies but converts fees to sterling to form part of the profit-share pot.

By contrast Allen & Overy, which bills mainly in sterling, except for the US where it bills in dollars, denies it has been affected by the pound.

Freshfields managing partner Ian Terry said most of his firm's clients in overseas offices were local and would not accept bills in sterling.

Discrepancies between the two sets of profit-per-partner figures produced by the two magazines appear to be due to how they decided to define an equity partner. In the case of Garretts, for example, Commercial Lawyer editor Michael Chambers said he counted all partners as salaried apart from two. Legal Business, decided that there were 49 equity partners and consequently placed Garretts at only number 51 in the table for profits per partner.

Similarly, Commercial Lawyer has given Ashurst Morris Crisp much greater profits because it counts 63 equity partners there. Ashursts said Legal Business's count of 73 was closer to the truth.