Profits at Severn Trent have been boosted by a strong performance from the company's waste management business.

Profits at the waste management arm - called Biffa - more than doubled following the purchase of UK Waste last year.

Severn Trent said it was "particularly pleased" with its purchase, and said it should start to save £15m a year after it has been fully integrated with Biffa.

Overall the group's pre-tax profits before interest, goodwill and exceptional items grew 10.6% to £210.6m.

After interest and goodwill allowances, profits rose 4.4% to £117.8m - slightly ahead of analysts forecasts.