Infrastructure CK Infrastructure Holding and water provider Castle Water are also understood to have submitted proposals to invest in Thames Water.
If the loan is approved Thames Water wants a full restructuring, taking in new shareholder investment and swapping debt for a portion of the company for existing creditors.
That's being provided by so-called A-class creditors who hold around £11bn in debt racked up by Thames Water Utility Holdings, the business that serves about 16 million customers in London and the South East.
Two sets of creditors both want to lend Thames Water the £3bn sum, with the company favouring the A-class creditors.
It's crunch time for the UK's biggest water provider Thames Water as its fate will be announced on Tuesday morning.
