A YEAR ago, investors in 21st Century Fox, Rupert Murdoch’s entertainment empire, could have been forgiven a bout of the blues. Shares were down by 30% from their peak in December 2014. Viewership of most of the company’s American networks was in decline, and millions had dropped expensive pay-TV packages, including its own, in favour of cheaper web-delivered video.

On May 25th Fox’s shares reached a new all-time high, rising above $39 a share. The business has not turned around, but Fox’s value has, as a prize for other media titans seeking global scale. Comcast, a cable giant, is preparing to top Disney’s $52bn all-stock offer for much of Fox (plus almost $15bn in debt) with an all-cash offer of at least $60bn. Disney is reportedly readying cash to sweeten its offer, which Fox’s board had approved in December. The final sale price could exceed $70bn. The winner will take on Netflix and Amazon in the competition for customers globally. The loser will be at risk of falling behind in that chase.

The bidding war, if it comes, will probably not begin until June 12th, when a federal judge in Washington is expected to rule on the government’s antitrust lawsuit seeking to block AT&T’s $109bn purchase of Time Warner. If that vertical merger of distribution and content goes through, Comcast will have a more credible case that its offer could pass regulatory muster. If the deal is blocked, Comcast may limit what it seeks to buy from Fox or focus on its £22bn ($29bn) bid for Sky, a European satellite broadcaster that was to be turned over to Disney in the Fox sale.

Fox’s size, rather than its trajectory as a business, explains the fervour of its suitors. Much like Randall Stephenson, the boss of AT&T, Bob Iger of Disney and Brian Roberts of Comcast have concluded that to compete with Netflix and other tech giants for customers in entertainment, they must achieve huge scale. Disney plans to launch a direct-to-consumer Netflix-like streaming service in 2019; Comcast, which owns NBCUniversal, probably would announce similar plans were it to add heft.

The assets that Mr Murdoch agreed to sell to Disney meet that need: Fox’s film and TV studios; its vast library of content, including “The Simpsons”; cable networks such as FX; international assets like Sky (pending Fox’s battle with Comcast for control of Sky); and Fox’s 30% stake in Hulu, which would give either Disney or Comcast, each of which also owns 30%, control of a streaming platform with 20m customers in America. (Mr Murdoch and his family would retain the flagship broadcast network and their national sports and news networks, including Fox News Channel, the company’s cash cow).

The stakes appear higher for Comcast. Disney’s enviable collection of film franchises should provide enough backing for a successful streaming service without Fox. Comcast, if it were to lose, would be left to hunt for much smaller prey to bulk up its offering. Lionsgate, a mini-studio, might be one target. Mr Roberts could also seek to prise Hulu or other properties from a Disney-Fox transaction. Either victor may need to surrender some assets as concessions to regulators.

The Murdochs prefer Disney, saying it is a better fit (they turned down an offer from Comcast in the autumn). On March 29th James Murdoch, Fox’s boss, reiterated this rationale at Code, a media conference in California. But the family holds only 17% of Fox. Other investors may well opt for Comcast’s cash over Disney’s shares; the cash is taxable but so would the shares be once sold. In the end most analysts believe Mr Iger will raise Disney’s bid by as much as it takes to get Fox. Either way Fox investors will not have minded the attention.