In the world of media, bigger remains better.

So in the wake of Comcast’s $30 billion takeover of NBCUniversal and Verizon Communications’ serial acquisitions of the Huffington Post and Yahoo, AT&T has bought one of the remaining crown jewels of the entertainment industry.

The telecommunications giant agreed on Saturday to buy Time Warner, the home of HBO and CNN, for about $85.4 billion, creating a new colossus capable of both producing content and distributing it to millions with wireless phones, broadband subscriptions and satellite TV connections.

The proposed deal is likely to spur yet more consolidation among media companies, which have already looked to partners to get bigger. This year, Lionsgate struck a deal to buy the pay-TV channel Starz for $4.4 billion. And the Redstone family, which controls both CBS and Viacom, has urged the corporate siblings, which split 10 years ago, to consider reuniting.

AT&T and Time Warner said both of their boards unanimously approved the deal.

“When Jeff and I started talking, it became clear to us very quickly that we shared a very similar vision,” Randall L. Stephenson, AT&T’s chief executive, told reporters on a conference call on Saturday, referring to Jeffrey Bewkes, Time Warner’s chief executive. “Time Warner, we believe, is the clear leader in premium content.”