The latest move in the multi-way struggle between Comcast, Fox and Disney makes it more likely Disney will end up with control of Fox’s entertainment assets and gives Comcast more financial leeway to secure the prize of Sky.
However, investors appear to think it may offer cover for Murdoch to bow out of the running for Sky, as Sky's share price dropped nearly 2% to 1,500p on the news.
The development comes five days after Comcast topped Fox’s previous £14-a-share offer to buy the 61% of Sky Fox does not already own with a £14.75 share for the whole company, valuing Sky at £26bn.
Comcast’s pull-out leaves Disney with a clear run at Fox’s entertainment assets – its film and television studios, cable entertainment networks and international TV business including its 39% Sky stake – which last December it agreed to buy for $66bn (£49.1bn).
Brian Roberts, chairman and chief executive of Comcast, said: "I’d like to congratulate Bob Iger and the team at Disney and commend the Murdoch family and Fox for creating such a desirable and respected company."
Roberts has previously said Comcast would be prepared to co-own Sky with either Fox or Disney, as long his company held the majority stake.