The New York Times said that Sky could become available if Rupert Murdoch's News Corporation was ordered to sell its 39.1% stake in the firm by UK regulators.
The paper suggested that Comcast could be interested in acquiring the pay-TV and internet service provider as a way to expand its global operation.
But D'Arcy Rudnay, a spokeswoman from Philadelphia-based Comcast, told Bloomberg: "This is complete rubbish, speculation and inaccurate."
The statement echoed a similar line from Comcast chief financial officer Michael J. Angelakis, who said in response to the story: "This is complete rubbish. It is total speculation and inaccurate."
But The New York Times is sticking by its report, which said that Comcast was in the preliminary stages of exploring a possible deal for Sky, without any formal offer or negotiations as yet.
Media regulator Ofcom is currently investigating whether News Corp is "fit and proper" to hold a UK broadcasting licence for Sky, following revelations of alleged corporate malpractice in the phone hacking scandal at the News of the World.
Last summer, the hacking affair prompted News Corp to withdraw its £8bn bid to acquire the remaining shares in Sky that it did not already own.
According to the New York Times sources, News Corp is considering divesting the Sky stake "at a premium" and pulling back from the business entirely.
This is because it does not want to be faced with offloading the stake for considerably less if Ofcom deems it unfit to hold a licence, effectively forcing a fire sale.
"There's a big difference between exiting a position like that on your own terms versus being forced to exit a big position in a forced-exit situation," media analyst Todd Juenger told the paper.
However, other commentators believe that it would be 'uncharacteristic' for News Corp to bow to pressure from a regulator such as Ofcom and sell its stake.
"On an emotional level, I find it hard to believe," said David Bank, a media analyst at RBC Capital Markets. "It would be a tacit admission that the British government is right."
The Times feels that acquiring the stake in Sky would be attractive for Comcast, as it would enable the firm to expand its international pay-TV operation.
With a market capitalisation of $80bn (£51bn), the US media giant could easily afford the deal, and it has not shied away from big acquisitions in the past, having spent $13.8 billion in early 2011 to take a 51% stake in NBCUniversal.