Thames Water said on Monday its investors had agreed to invest 750 million pounds ($960 million) into the troubled company but Britain's biggest water business warned it would need further funding in the years ahead.

Thames Water, weighed down by 14 billion pounds of debt, is under pressure to fund its turnaround and had wanted shareholders to stump up an extra 1 billion pounds.

Investors will provide 750 million pounds, the company said in a statement on Monday, and they have indicated they will pump in 2.5 billion pounds over the 2025 to 2030 regulatory period.

"This further funding is subject to satisfaction of certain conditions, including the preparation of a business plan that underpins a more focused turnaround that delivers targeted performance improvements for customers, the environment and other stakeholders," it said of the initial investment.

Thames Water's owners include Ontario Municipal Employees Retirement System, the UK's Universities Superannuation Scheme and China Investment Corp. ($1 = 0.7812 pounds) (Reporting by Sarah Young; Editing by Kate Holton)