It is preparing a formal offer for the assets that Fox had agreed to sell to Disney
Comcast has confirmed it is considering a bid to beat Disney to win control of 21st Century Fox's TV and film businesses.
The US cable giant said it was in the advanced stages of preparing a formal offer for the assets that Fox had agreed to sell to Disney.
It said any bid would be at a premium to the value of the current $52.4bn (€44.8bn) all-share offer from Disney.
It said in a statement: "While no final decision has been made, at this point the work to finance the all-cash offer and make the key regulatory filings is well advanced."
The current Disney bid also covers the intended purchase of the 39.1% stake in Sky that Fox currently owns.
The €20bn Fox bid to buy the shares in Sky it does not have has become mired in regulatory hurdles in the UK, with Fox awaiting a decision within weeks on whether its remedies to satisfy media plurality concerns will prove acceptable to the government.
Those offers included the potential for Sky News to be owned by Disney - bypassing concerns that Rupert Murdoch's family would have too much control over UK media.
Comcast, last month, launched a €25bn rival offer for Sky - prompting the possibility of a bidding war.
The UK's Culture Secretary Matt Hancock, who will rule on whether the Fox takeover of Sky could potentially proceed, said earlier this week that he was "not minded" to refer the Comcast offer to the Competition and Markets Authority (CMA) for deeper scrutiny on public interest grounds.
Comcast said of its intention to bid for the Fox assets: "While no final decision has been made, at this point the work to finance the all-cash offer and make the key regulatory filings is well advanced."