The chief executive of Thames Water has stepped down after failing to turn around the performance of one of the UK's largest utility companies.
Steve Robertson will be replaced with immediate effect.
A source close to the company said the firm wanted someone with "a mind for operations".
Thames Water, which manages water supplies and waste water, has struggled with leaks, falling profits and increasing customer complaints.
The firm said that Mr Robertson, who was appointed chief executive in September 2016, had "successfully transformed" the firm "in a challenging environment" but that he was leaving by mutual agreement.
But Thames Water has been criticised for not being able to bring the number of leaks under control.
In December the firm said last spring's cold weather had caused pipes to burst, while the summer heatwave had brought supply problems.
Since 2017, Thames Water has been fined more than £128m for poor management of leaks.
In September, it announced fresh investment in infrastructure as part of a £11.7bn five-year plan.
Thames Water said under Mr Robertson's tenure it had "increased its focus on customer satisfaction, improved incident response capabilities, expanded support for vulnerable families and invested more than £2bn in the network to improve overall performance".
Ian Marchant, interim executive chairman, who will lead the company while a permanent replacement is found said: "We need to continue to ensure that Thames Water is an organisation that both customers and staff feel proud of."
The future of the water industry has recently become a hot political issue, with Labour saying it would take it back into public ownership if elected.
Water firms were sold off by Margaret Thatcher's Conservative government in 1989.