Industrial equipment rental firm Ashtead posted a 22% drop in full year pre-tax profit, but said its 2009/10 guidance remains unchanged.Underlying pre-tax profit from continuing operations before exceptionals was £87m in the year ended 30 April compared with £112m last time, while revenue was up 2% at 1.074bn.Revenues in both the US and UK markets were adversely affected by lower volumes and yields although Ashtead continued to benefit from the stronger dollar.The group said its cost reduction programme announced in December is now fully implemented, delivering operating cost savings of at least £100m. The final dividend of 1.675p per share is unchanged, making 2.575p for the year (2008: 2.5p)."Whilst infrastructure and utility work continues to hold up, the relative lack of finance available for private sector commercial development makes it inevitable that construction volumes overall will remain weak," said chief executive Geoff Drabble."We continue to believe that the fundamentals of our markets remain attractive and that, with our continuing focus on meeting the challenges of current market conditions and on cash generation, we are well positioned for the next phase of the cycle," he added.