Network Ten appears on increasingly shaky ground as new doubts emerge on whether the three billionaires who agreed to guarantee a $200 million lifeline in 2013 will extend the same support for the next round of funding.

That scenario raises the real possibility of Ten falling into the hands of administrators unless corporate advisers are able to find alternative sources of funding.

The company is expected to tell the market on Tuesday morning that major shareholders have decided not to personally guarantee the company's debt when it applies for a new $250 million loan in December. Well-placed sources confirmed reports over the weekend in the Australian Financial Review that Lachlan Murdoch, with 7.5 per cent, and Bruce Gordon, with 15 per cent, would end their personal guarantees.