Osborne Clarke has reported a 12% rise in revenue for the first half of 2013-14, following a period of investment over the past two years.

The firm's revenue grew to £60.7m, up from the £53.4m recorded at the 2012-13 half-year mark. Osborne Clarke's offices in London, Bristol and Reading brought in revenue of £39.1m, 8% up on the equivalent point last year.

The firm identified its Spanish office as the standout performer after it grew its revenue by 25%.

The firm's results were boosted by office launches in Brussels and Paris in June and July respectively. The firm's new office in Manhattan, which launched in October, will count towards the firm's year-end results.

Key mandates for Osborne Clarke in the first half of the year included acting for Spanish pharmaceutical company Grifols, a longstanding client, on its $1.7bn (£1.05bn) acquisition of Switzerland's Novartis, and representing Foresight Solar Fund on its £43.7m acquisition of Wymesworld Solar Plant, the largest solar park in the UK.

The firm has also advised the Environment Agency Pension Fund on its transfer of services to a hub operated by Shared Services Connected, a £1bn joint venture between the Cabinet Office and Steria.

Other firms to have announced improved half-year results so far include Simmons & Simmons (8% up), Allen & Overy (7% up), DWF (58% up), Clyde & Co (16.5% up), Hill Dickinson (6% up), Field Fisher Waterhouse (7% up), and Olswang (15% up).

Berwin Leighton Paisner, Clifford Chance, Freshfields Bruckhaus Deringer, Linklaters, Ashurst and Macfarlanes are among other firms to have seen revenue increase in the past six months.