The Gulf state of Qatar has emerged as a front runner in a bidding war for Thames Water.
Qatar may pour billions of pounds into a bid for Thames Water
An official with Qatar's Investment Authority confirmed his government's interest in buying Thames Water from German owner RWE.
Hussain Al Abdulla declined to reveal how much the state-owned investment authority had bid for Thames Water.
However, he said the bids already in from interested parties had ranged between £7bn and £10bn.
Thames Water supplies water to eight million people across London and the South of England and provides sewage services to 13 million customers.
The first round of bidding for Thames Water ends this week.
Mr Abdulla expressed confidence over Qatar's chances. "I think we have a good opportunity to win the bid," he said.
The Investment Authority is the state investment arm of Qatar, which is an Opec member and possesses the world's third largest reserves of natural gas.
RWE chief executive Harry Roels said he was conducting talks over Thames Water with potential buyers in August. The company wants to sell both its UK and North American water operations.
RWE is a utility giant with interests in gas, electricity and recycling. It bought Thames Water for £4.8bn in 2000.