Pinsent Masons has made up 20 associates to the partnership this year, making 2007 the single largest round of promotions in the firm's history.
Pinsents made up 16 in the UK, two in Dubai and two in Hong Kong. The corporate, employment, construction and property groups were the biggest winners, with four new partners apiece.
Managing partner David Ryan said: "We're very fortunate to have a wealth of new talent in the firm."
Promotions are 66 per cent up on last year, when 12 were made up. Construction and property have proved the best departments for partnership prospects, with each making up three new partners last year.
This year the banking and finance and dispute resolution groups received one new partner each, while the technology team gained two.