Plumbing supplies group Wolseley posted a 20 per cent rise in third-quarter trading profit and said it was on track to meet analysts' full-year expectations, helped by strong revenue growth in its largest market, the United States.

The company, which operates the Plumb Center and Ferguson chains in the United States and Britain, said trading profit at constant exchange rates rose to £195 million in the three months ended April 30.

"It's a very strong profit performance and that's quite hard to find in these markets," said Charles Stanley analyst Tony Shepard. "Although that is probably in line with expectations, it's still good to see it being delivered."

Revenue climbed 7.5 per cent on a like-for-like basis in the third quarter and the company kept its forecast for growth of around six per cent over the next six months.

In the United States, which accounts for almost two-thirds of the group total, like-for-like revenue rose 8.3 per cent. It was up 7.6 per cent in Britain and up 8.8 per cent in Nordic countries.

Wolseley is expected to make a full-year underlying profit of £775 million, according to analysts.

The company completed three acquisitions in the third quarter, with a total annualised revenue of £69m.

Finance chief John Martin said it was taking a cautious stance on deals and would probably not reach its average annual spending on acquisitions of between £200m and £300m.

"We have a strong preference to buy good businesses ... and there haven't been that many around," he said.