The move will be a particular blow to the West End firm. Bertram is one of the main points of contact for Harbottles in its relationship with key client Chrysalis and led the team on the sale of Air Studios by the company earlier this year. He resigned in August, but is still negotiating the terms of his exit.
Harbottles, once a stalwart of The Lawyer's top 100 firms, dropped out of the list in 2004 when its revenue fell to around £13m from a peak in 2002 of £15m. The firm's revenue was back up to £15.5m for the 2005-06 financial year, but the average profitability of the all-equity, pure lockstep firm is believed to be significantly lower than Olswang's. The larger firm posted on average profit per equity partner of £571,000 last year.
Bertram qualified at Linklaters in 1991 and joined Harbottles in 1996, becoming a partner in 1999. He advises on most corporate matters, including start-up and growth capital sourcing and structuring, IPOs and other exit strategies.