United Utilities has said it expects underlying operating profit to be slightly higher than last year due to the tight management of costs.

In a trading update, the utility said current trading is in line with its expectations for the year ending 31 March 2013 and expects to invest £750 million in 2012/13, compared with £680 million in the prior year.

Revenue is expected to increase at a rate slightly below the allowed regulated price rise for 2012/13 because of the impact on commercial volumes from the challenging market conditions.

Group net debt at 31 March 2013 is expected to be slightly higher than the position at 30 September 2012. This principally reflects expenditure on the regulatory capital investment programme, payment of the 2012/13 interim dividend and payments in relation to interest and tax, largely offset by operational cash flows, the company said.

United Utilities will announce its full year results on 23 May 2013.