(Reuters) - British industrial equipment hire group Ashtead Group Plc (>> Ashtead Group plc) said on Wednesday it expects full-year results to exceed its forecasts, helped by strong growth in its North American business.

The company's stock rose as much as 9.3 percent to 1375 pence, making it the biggest percentage gainer on the FTSE 100 <.FTSE>.

Ashtead, which has benefited from a rebound in the U.S. construction market, said its U.S. unit, Sunbelt, reported a 14.2 percent rise in underlying pretax profit in the first quarter ended July 31.

The unit contributed about 86 percent of the company's revenue in the quarter.

Ashtead's U.S.-based peer United Rentals Inc (>> United Rentals, Inc.) said in July that it saw solid customer activity on both the East and West Coasts of the U.S. and reported better-than-expected second quarter results.

Ashtead's underlying pretax profit rose 4 percent to 183.6 million pounds in the first quarter.

Group rental revenue jumped 12 percent to 660.8 million pounds, the company said.

Weaker pound also helped the results, Ashtead said, as the currency fell to its lowest level in more than 30 years after Britain voted on June 23 to leave the European Union.

Jefferies, which has a "buy" rating on the stock, raised its full-year revenue forecast for the year ending on Oct. 31, 2017 to 2.94 billion pounds from 2.73 billion pounds.

The company's shares were trading up 5.9 percent at 1332 pence as of 0858 GMT.

(Reporting by Rahul B in Bengaluru; Editing by Sunil Nair and Amrutha Gayathri)

Stocks treated in this article : United Rentals, Inc., Ashtead Group plc