A bidding war for utility Thames Water is due to go a stage further with several groups circling the firm estimated to be worth £7 billion.
Australian utility group Alinta is the latest to be linked to the water company, which has been put up for sale by its parent German RWE.
Alinta may team up with Australian bank Macquarie or they could compete against each other, it is suggested.
The government of Qatar, Guy Hands' investment vehicle Terra Firma, French water group Veolia and a consortium which includes Borealis, the Canadian pension fund and 3i, have also been reported to be involved ahead of today's deadline for first round bids.
RWE wants to offload Thames Water and American Water so it can concentrate investment on its European electricity and gas markets, which includes Worcester-based npower.
Thames Water, which has 13 million customers in London and the South-east, has come under fire for missing its targets on leakage rates.
Last week, RWE reported first half operating profits of more than four billion euros - an increase of 19 per cent.
RWE, which has energy operations worldwide, said power prices helped profits to 4.1 billion euros (£2.76 billion) in the six months to June 30.