Deloitte has warned of tough times ahead as it revealed that it had surged through the £1.55bn revenue ceiling after delivering growth of 15% for the year ended 31 May 2006.

The firm, which is aiming to reach revenues of £2bn by 2008, grew most strongly in consulting, where revenue rose 22% to £381, and audit, where revenues were up 17.2% to £487m. Corporate finance grew 10.2% to £265m and tax was up 10.1% to £426m.

Deloitte chief executive John Connolly, however, warned that the buoyant period the profession has enjoyed over the last year could be coming to an end.

'The markets will be tougher in the year ahead. The complex interaction of the turmoil in the Middle East, oil prices, fear of inflation, a slowing US economy and now the recent UK interest rate increase impact corporate confidence and there is already evidence of this,' Connolly said.

Connolly said he was pleased with the firm's performance over the last year. During the period Deloitte won the FTSE 100 audit of Scottish Power and increased its market share in the FTSE 350 to 23%. This gave Deloitte the second largest audit presence in the FTSE 350.

In tax, which Connolly described as 'still very challenging', Deloitte benefited from REIT legislation and advising on tax efficiency at companies with global operations. Connolly said consulting had grown from 'strength to strength' and that corporate finance had benefited from high growth in merger and acquisition advice.

Connolly, who earned £4.1m compared with £3.2m last year, said that average profit per partner had climbed from £711,000 in 2005 to £765,000 in 2006.