Macfarlanes is to promote an unprecedented six lawyers to the partnership this year, the largest single group in its history.
The highly profitable London firm - it was second only to Slaughter and May in last year's The Lawyer UK 100 Annual Report - has just 63 partners, so when the appointments take effect on 1 May, the partnership will grow by almost 10 per cent.
In another first, the six include Paul Davies, a former environmental head of legal for Schlumberger's Eastern Hemisphere Operations, who will become Macfarlanes' first environmental law partner. It is understood that a blue chip organisation appointed Macfarlanes to its environmental law panel last year.
Senior partner Robert Sutton said: "We just had an exceptional generation and if you're an excellent person here, you'll become a partner, if you're not, you won't."
Sutton conceded that there was also a very good business case for expanding the firm in commercial, environmental, private client, and private equity/corporate - the four areas where the partners were made up.
Other than Davies, the partners all started at Macfarlanes as trainees, reinforcing the firm's cult-like image.
The private client department, which gains three new partners, also has a new head, Jonathan Conder, who replaces incumbent John Rhodes.
Conder said: "This 50 per cent increase in the number of private client partners reflects consistent growth in the quality and quantity of the client base."