21st Century Fox Inc., locked in a global M&A showdown with two other media giants, followed through on its bid to buy U.K. broadcaster Sky Plc, though it didn’t move to top a rival offer from Comcast Corp.

The company formalized a previously announced bid of 14 pounds a share for the 61 percent of Sky that it doesn’t already own, according to a regulatory filing on Tuesday. It still has an opportunity to raise its bid above Comcast’s 14.75 pound-a-share price.

Fox shareholders approved a $71 billion takeover deal with Walt Disney Co. last month, setting the stage for a huge swath of media assets to change hands, including 20th Century Fox, a stake in Hulu and cable networks such as FX. Disney also would get Fox’s current 39 percent stake in Sky -- and a shot at acquiring the rest of that business.

As it formalizes its Sky bid, Fox switched the structure from a scheme of arrangement, which requires approval from 75 percent of Sky’s shareholders, to an offer. That threshold requires potentially as little as 50 percent.

The move also starts a 46-day clock during which Comcast and Fox can change their offers. Sky acknowledged the publication of Fox’s offer and said it would publish its formal response within 14 days, as set out under U.K takeover rules.

Investors are waiting for a peek into the strategy over the next two days, when both Disney and Fox report their quarterly earnings. Disney’s results come after the bell on Tuesday, while Fox is delivering its numbers on Wednesday afternoon.

One question for investors will be whether Disney can justify its $71 billion offer for Fox without also owning all of Sky. Another concern: Can Disney launch its nascent streaming platform in Europe without the content that is available via Sky?

Analysts have speculated that Burbank, California-based Disney could agree to a deal with Comcast that might involve swapping portions of Hulu and Sky -- and potentially renegotiating distribution rights over Disney and Fox content with the British broadcaster.