Grant Thornton, the UK's fifth largest accountancy firm, has revealed it is on course to reach its goal of £500m in revenues by 2015 after posting an 11% increase in fee income.

The firm, which is the largest outside the Big Four, said revenue had hit £417m for the year ended 30 June 2012, while pre-tax profits had increased by £1m on last year's £75m.

But the average distributable profit per partner has slipped 2% to £335,000.

Scott Barnes, Grant Thornton's chief executive, said: 'We are very realistic as the market remains tough and we do not expect growth to be driven by any economic upswing. We have invested strongly for sustainability, and shall continue to do so, achieving our growth ambitions through increased market share and investments to deepen and widen our capability.'

During the year, the firm won a number of Audit Commission contracts, which Barnes said confirmed the firm's ability to undertake audits of large and complex organisations.

However, overall revenue for the firm's assurance practice remained flat at £120m. Taxation services grew by 3% to £92m while the firm's advisory practice, which includes corporate finance and recovery and reorganisation work, jumped 22% to £205m.

The firm said the dip in partner profits was due to investments made by the firm over the year, including new offices in Cambridge, Reading, Belfast and Birmingham. Some 20 new partners and more than 300 trainees were appointed during the year.

Barnes said: 'The partnership has delivered a strong result for the year, which is ahead of expectations and testament to our core strategy and the hard work and vision of the people within the business.'