The British firm, which makes over 80 per cent of revenue from its US unit Sunbelt, said today that its underlying pre-tax profit rose 82 per cent to £61.4m in the three months to the end of July. Revenues rose 18 per cent to £325m.
"The markets in which we operate have performed as anticipated with gently improving conditions in the US and a more challenging outlook in the UK," said Ashtead chief executive Geoff Drabble.
"Given the momentum established in the business, we now anticipate a full-year result materially ahead of our previous expectations."
The company was previously expected to report an average pre-tax profit of £162.2m the year to the end of April 2013, according to poll of analysts.
The company said slow construction markets continued to push cash-strapped customers to rent rather than buy expensive industrial equipment.
Ashtead, which hires out equipment from diggers to small tools, said first quarter sales at Sunbelt rose a quarter to £275.3m.