"For now, Comcast seems to be in pole position, but it's not a slam dunk. There's so much to play for and expect both companies to open up the war chest," Paolo Pescatore, an independent telecom and media analyst, told CNBC via email on Monday.
"This represents a great opportunity to own a prized asset which will prove to be a worthy long-term investment," he added.
On Tuesday, Bloomberg, citing people familiar with the matter, reported that the takeover battle for Sky would likely be settled at a brief auction.
In such auctions, bidders submit secret offers to a third-party arbiter. And while this method is relatively common for commercial transactions, it is extremely unusual when it comes to deal-making for such a high-profile public company.
Britain's Takeover Panel — the body that regulates U.K. mergers and acquisitions — would administer an auction, drawing the curtain on one of the U.K.'s longest-running takeover battles.
Sky's appeal to U.S. media firms is such that owning the company would give them both a rare opportunity to diversify out of North America and reach consumers more directly. It has a stock market value of around £26.8 billion ($35 billion).
"It is so close to call that a sealed bid will be the only way to decide the outcome," Pescatore said.