The deal, announced on Sunday, comes as Comcast awaits regulatory approval of its $45 billion bid for Time Warner Cable, a transaction that has the potential to transform the television landscape by creating a new cable and broadband Internet powerhouse.
AT&T said it is offering $95 per DirecTV share in a combination of stock and cash, a 10 percent premium over Friday's closing price of $86.18. The cash portion, $28.50 per share, will be financed by cash, asset sales, financing already lined up and other "opportunistic debt market transactions."
Analysts said the deal would help support AT&T's dividend even as it confronts tougher competition from upstart T-Mobile USA and other cellular operators that have pressured its average revenue per user.
"This is financial engineering," said Kevin Smithen, an analyst at Macquarie. "It is a transaction that secures the dividend for many years, taking advantage of AT&T's relatively high valuation and low interest rates to do an accredited acquisition that will bolster its free cash flow."
To facilitate regulatory approval, AT&T will sell its roughly 8 percent stake in Carlos Slim's America Movil. DirecTV has some 18 million customers throughout Latin America, in addition to its 20 million U.S. subscribers.
AT&T said it expects the takeover to deliver cost savings at an annual rate of $1.6 billion by the third year after closing.
"This is a unique opportunity that will redefine the video entertainment industry and create a company able to offer new bundles and deliver content to consumers across multiple screens - mobile devices, TVs, laptops, cars and even airplanes," AT&T Chief Executive Randall Stephenson said in a statement. "At the same time, it creates immediate and long-term value for our shareholders."