Fewer than 1 percent of Sky PLC shareholders in Europe have taken up Comcast Corp.'s $31 billion buyout offer so far, waiting for a higher bid from 21st Century Fox and the Disney Co.

Comcast has told U.K. regulators that stockholders tendered only 0.21 percent of Sky shares — or 3.8 million out of a total of 1.7 billion —  by Wednesday's deadline in the U.K., prompting the Philadelphia cable giant to set a new deadline of Sept. 12.

Comcast's offer to Sky shareholders amounts to $18.91 a share, while one from 21st Century Fox, in conjunction with Disney, is $17.95 a share, based on Thursday currency exchange rates.

Sky shares closed on Thursday in London at $19.74, indicating that investors believe there could be another bid. After months of speculation, most of the big Sky shareholders today are institutions or hedge funds.

"All the body language suggests that Disney will raise its bid" for Sky, Neil Begley, senior vice president at Moody's Investors Service, said on Thursday. Although Fox has an existing competing bid for Sky to shareholders, "it's really Disney's decision at this point," he added.

Sky is an unresolved aspect of the takeover battle between Comcast and Disney for Fox's global entertainment assets that began in late 2017. Disney won that contest this summer with $71.3 billion in stock and cash, with both Fox and Disney shareholders approving the deal in late July. Among the assets in the Disney/Fox transaction is a 39 percent stake in Sky. Fox and Disney would like to own 100 percent of Sky, which is what it would accomplish with its existing offer.

But Comcast is seeking to carve off Sky for itself.

Comcast has aggressively bid for Sky as it sees it as a launching pad for a global TV business. Sky has about 23 million subscribers in the U.K., Ireland, Germany, Austria, Italy, Spain, and Switzerland, offering streaming products, satellite pay-TV services, and content such as Sky News.