United Utilities said it was trading in line with expectations with a jump in revenue in the period from April 1st to July 25th.In a trading update on Friday, the company said the rise in revenue reflected price increases for 2013/14. However, the incline was slightly below the allowed regulated price rise, mainly due to the impact of a tough economic climate on commercial volumes.Higher depreciation and other operating costs also offset the improved revenue.As planned, capital investment continued at high levels as United Utilities maintained and improved services for customers.Regulatory capital investment for 2013/14, including infrastructure renewals expenditure, is expected to be around £800m.The group said its financial position remains robust with net debt marginally lower at about £156m, compared to the end of March, despite high levels of capital investment. United Utilities expects to deliver a "good underlying financial performance for 2013/14"."The business will continue with its strong focus on customer service through sound operational performance and sees plenty of opportunities for further improvements," the company said. Shares fell 0.14% to 716.50p at 09:17 on Friday.