21st Century Fox shareholders will benefit the most from AT&T’s major legal victory in its pursuit to buy Time Warner, according to one Wall Street firm.

On Tuesday, U.S. District Court Judge Richard Leon ruled that AT&T could buy Time Warner with no conditions attached, denying a U.S. Department of Justice antitrust challenge to the deal.

Jefferies reiterated its buy rating for 21st Century Fox shares, predicting Disney and Comcast will fight each other vigorously to acquire the company in a seemingly “more lenient regulatory environment” for mergers.

In December Disney announced a deal to acquire many parts of 21st Century Fox for $52.4 billion in stock.

“We see FOXA as a clear winner following today’s ruling, as it will likely set off a bidding war between CMCSA and DIS,” analyst John Janedis said in a note to clients Tuesday. “Given FOXA’s strategic importance, we expect both to stretch their B/S [balance sheets], but retain investment grade ratings, translating to a max bid of $42.50/$80B – ex Sky.”

Janedis expects Comcast will make an official offer for 21st Century Fox, followed by another bid from Disney.

“We believe Disney will respond to a CMCSA bid with a counter offer, as both companies view the FOXA/Sky assets as key to competing globally,” he said.

Disclosure: CNBC is owned by Comcast’s NBCUniversal unit.