The Justice Department said Thursday it is appealing the ruling last month by U.S. District Judge Richard Leon, which blessed one of the biggest media deals ever following a landmark antitrust trial.

Leon rejected the government's argument that the phone and pay-TV giant's $81 billion takeover of the entertainment conglomerate would hurt competition, limit choices and jack up prices for consumers to stream TV and movies.

Leon's ruling allowed Dallas-based AT&T to absorb the owner of CNN, HBO, the Warner Bros. movie studio, "Game of Thrones," coveted sports programming and other "must-see" shows.

Last month, District Court Judge Leon approved AT&T's proposed $85 billion purchase of Time Warner, a corporate combination that promises to unleash even more megamergers in the fast-changing media business.

The judge's opinion permitted the merger to go forward with no conditions, according to CNBC and Reuters. The Trump administration had opposed the merger, which promises to join one of the country's biggest telecom providers with a media giant.

Leon previously approved Comcast's acquisition of NBCU in 2011. In that case, he added a list of conditions the new entity was required to follow. Among those, Comcast agreed not to gouge competitors who wanted to carry NBC content and not to create a service entirely made up of Comcast or NBC content.

The Justice Department had pressured Time Warner to sell Turner Broadcasting, which includes the cable news operation CNN, or other segments of the business -- suggestions the companies resisted. 

DOJ had said in a statement that it was "disappointed with the Court's decision today. We continue to believe that the pay-TV market will be less competitive and less innovative as a result of the proposed merger between AT&T and Time Warner. We will closely review the Court's opinion and consider next steps in light of our commitment to preserving competition for the benefit of American consumers."

"There's a presumption in these vertical cases, an economic presumption, that they are likely to benefit consumers or at least be competitively neutral. Whether that happens in practice is an open question," said Schaeffer, the attorney.

Leon, the judge in this case, previously approved Comcast's acquisition of NBCU in 2011. In that case, he added a list of conditions the new entity was required to follow. Among those, Comcast agreed not to gouge competitors who wanted to carry NBC content and not to create a service entirely made up of Comcast or NBC content.

The Justice Department had pressured Time Warner to sell Turner Broadcasting, which includes the cable news operation CNN, or other segments of the business, which both companies resisted. They've now won that bet. Time Warner shares were up nearly 5 percent in after-hours trading.

(The Associated Press, CBS News contributed to this report.)