Canadian, Kuwaiti investors take stake in UK's Thames Water

* Borealis, Wren House take 26.3 pct stake

* Stake in Kemble Water bought from Macquarie funds

* No financial details disclosed (Adds detail from two statements, adds quotes, background, bullet points)

By Simon Jessop

LONDON, March 14 (Reuters) - A consortium of Canadian and Kuwaiti investors has agreed to buy a minority stake in Britain's Thames Water from funds managed by Macquarie, ending the Australian group's 11-year investment in Britain's largest water firm.

The deal is the latest high-profile acquisition of British infrastructure by overseas investors, as pension schemes, sovereign wealth funds and others look to tap into stable returns tough to find in other financial markets.

Canadian pension fund investor Borealis Infrastructure and the infrastructure investing arm of the Kuwait Investment Authority (KIA) are buying a 26 percent stake in Kemble Water Holdings, the holding company of Thames Water.

Borealis, infrastructure investment manager for OMERS, the pension plan for Ontario's municipal employees, and Wren House Infrastructure Management, the infrastructure arm of the KIA, said they had agreed to buy the stake from Macquarie Infrastructure & Real Assets.

No financial details were disclosed.

Thames Water is Britain's largest water and wastewater services provider, with 15 million customers across London, the Thames Valley and surrounding areas. It supplies 2.6 billion litres of drinking water per day.

"The Consortium has met with Thames Water's existing management team and... will support Thames Water's ongoing 4.5 billion pound capital investment programme - for the 2015 to 2020 regulatory period - the largest in the UK water industry," Borealis and Wren House said in a joint statement.

Macquarie, in a separate statement, said its Macquarie European Infrastructure Fund 2, which held most of the stake, was divesting as it approaches maturity and the deal would end the group's involvement with Thames Water.

During its tenure, Thames Water invested more than 11 billion pounds, or around 1 billion pounds a year, more than twice that invested during the five-year period before privatisation in 1989, it said.

"Today, Thames Water is undoubtedly a better, stronger and more customer-focused business than that which we invested in back in 2006," said Martin Stanley, global head of Macquarie Infrastructure and Real Assets.

(Reporting by Simon Jessop; editing by Lawrence White and Jason Neely)