Walt Disney Co. and 21st Century Fox shares were in the spotlight Wednesday amid reports the two media-entertainment powerhouses were readying a major deal for some of Fox's prized television and film assets.

Some reports said the deal -- in which Disney would acquire the famed Fox Hollywood studios and key television operations of the Murdoch family-controlled group -- could be announced as soon as Thursday.

Fox shares were down 3.6 percent at $32.87 in mid-morning trade, in a pullback after sharp gains over the past few weeks. Disney shares were nearly unchanged at $107.40.

According to CNBC television and The Financial Times. Disney is expected to pay $60 billion for the assets. CNBC said the deal would give Fox shareholders 25 percent of an expanded Disney empire.

Disney is believed to be bidding for the Fox studios known for their film and television productions as well as the cable channels FX and National Geographic, plus the company's 39 percent stake in British-based pay TV group Sky.

The deal would likely shrink the empire created by billionaire Rupert Murdoch, and controlled by him and his two sons, leaving the Fox broadcast network, Fox News and sports cable channels.

The tie-up is seen as a response to the shifting landscape in the media-entertainment sector disrupted by streaming giants such as Netflix and Amazon.

The plan could nonetheless face scrutiny from antitrust regulators because it could concentrate power in the Hollywood studios -- and potentially in broadcast sports.

Analyst Brian Wieser of Pivotal Research said a reduced Fox "may lose scale and related efficiencies with the transaction, (but) may benefit from focus, financial leverage and changes to US media ownership rules."

In a research note, Wieser said that "international exposure is likely positive for Disney (and) the loss of international exposure is negative for Fox."