AT&T Inc., the second-biggest U.S. mobile-phone carrier, is in talks to acquire satellite-television company DirecTV, people familiar with the situation said Wednesday.

DirecTV is working with Goldman Sachs Group Inc. as it explores a sale, one of the people said, asking not to be identified discussing private information. After rising 43 percent in the past year, DirecTV has a market value of $45 billion.

Representatives for the companies declined to comment, as did a spokesman for Goldman Sachs. The Wall Street Journal earlier reported that Dallas-based AT&T approached DirecTV about a potential acquisition and that Goldman Sachs is working with DirecTV as the companies hold talks.

Comcast Corp.’s plan to acquire Time Warner Cable Inc. — to create an even bigger provider of both TV and Internet in the U.S. — is accelerating the need for consolidation in the rest of the industry. Meanwhile, the pool of pay-TV customers is peaking as viewers increasingly watch video online, making fast broadband connections a key offering.

Separately, Dish Network Corp. Chairman Charlie Ergen has contacted El Segundo, California-based DirecTV to discuss a merger of the two satellite-TV companies, people with knowledge of the matter said March 26.