Comcast is unlikely to make another bid for Twenty-First Century Fox's movie and television assets, focusing on a bid for Britain's Sky television, sources told CNBC's David Faber.

CNBC parent Comcast was engaged in a bidding war with Disney over the Fox assets. Recently Disney threw some cash into its own bid, raising its offer to $71 billion and edging out Comcast's bid of $65 billion in cash.

Comcast has also been bidding for Britain's Sky, which is 39 percent owned by Fox. Last week, Fox raised its bid for the remaining portion of Sky it doesn't own, with a new offer valuing the deal at $32.5 billion. And then last week Comcast raised its bid, valuing the company at $34 billion.

Sources told CNBC's Faber that Comcast is focused on its bidding for Sky.

The government's decision to appeal a recent court ruling allowing AT&T to go ahead with its purchase of Time Warner may be giving Comcast reason to pause in its pursuit of the Fox assets, Faber said Monday on CNBC. The government had tried to block the AT&T deal on competitive grounds.

There is also a belief, Faber said, that Rupert Murdoch, Fox's executive co-chairman whose family has a nearly 39 percent stake in Twenty-First Century Fox Class B shares, favors a deal with Disney.

In a regulatory filing last week, Disney said that Fox may elect not to boost its offer for Sky, and that any increase in the debt financing for Sky would require Disney's consent, which it may not elect to provide.

Shares of Comcast closed up 0.8 percent, while shares of Fox fell 1.7 percent. Disney shares closed up 0.2 percent.

Disclosure: Comcast is the parent company of CNBC.