BILLS for up to 10 million customers served by two water companies are to rise next year, industry regulator Ofwat warned today.

The changes, which are still subject to public consultation, will result in a £26 increase in the average annual bill for Northumbrian Water users and a rise of £9 for customers of North West-based company United Utilities.

Ofwat said an increase in the costs faced by the two companies were substantial enough to justify an increase in water and sewerage charges. It stressed the rises, which cover the year from April 1, still left bills for both companies at the same level, or below, as in 1999.