(Sharecast News) - Heavily indebted utility provider Thames Water will look to convince industry regulator Ofwat to allow it to hike consumer bills by as much as 44% over the next five years.

Thames Water intends to spend at least £1.1bn more on environmental measures on top of the £18.7bn it had originally proposed to spend between 2025 and 2030 and has also proposed the idea of increasing customer bills by 40%, excluding inflation, over the same five-year period.

Ofwat dismissed Thames Water's original proposal, leading to questions over the future of the firm, which has roughly £14.7bn of debts and has also come under fire for water leaks and sewage spillages.

Thames' new proposed total investment of £19.8bn will require bills to rise by 40%, reaching an annual average bill of £608.30 by 2029-30. However, Thames also said it could potentially increase investment by another £1.9bn, which would see average bills rising 44% to £627.

A final decision from Ofwat will likely come on 23 Ma, with a "draft determination" of what companies will be allowed to charge from next year to follow on 12 June.

Reporting by Iain Gilbert at Sharecast.com