The commission is requiring AT&T to expand its high-speed, fiber-optic broadband Internet service to 12.5 million customer locations and eligible schools and libraries. That’s about 10 times its current size. The F.C.C. said this addresses the concern that the merger would eliminate one choice for television service in the areas where AT&T and DirecTV previously competed. By expanding Internet service, the commission said, consumers will have more options to use services that rely on broadband to deliver video, such as Netflix, Amazon and Hulu.

AT&T also will be required to offer broadband services to people with low incomes at discounted rates.

Mr. Copps questioned whether the conditions were sufficient, saying that the commission did not have a good track record in making sure that they are fulfilled. “I have seen so many lofty merger commitments before and seen the companies find loopholes in them and weasel their way out of them,” Mr. Copps said.

But one of the commissioners, Mignon L. Clyburn, defended the broadband rationale. Ms. Clyburn noted that while she thought the public interest benefits were significant, she had concerns about the deal’s impact on smaller cable companies and independent programmers. To that end, she asked the F.C.C. chairman to start a proceeding to look at the “challenges and barriers to independent and diverse programming.”

Another concern about the deal is that AT&T is the only major Internet service provider whose customers face “data caps” for broadband service. The merger could increase the incentive of AT&T to deploy such usage-based pricing to limit access to online video in favor of its own traditional television service. As a condition of the deal, regulators forbade AT&T from deploying discriminatory practices that would disadvantage online video services.

“What they are basically saying is you have to treat everybody like you treat yourself, and so I think that is probably the most important protection against anticompetitive practices,” said Gene Kimmelman, the chief executive of Public Knowledge, a consumer advocacy group, and a former antitrust official at the Justice Department.

The company also will be required to submit its so-called interconnection agreements for review by the F.C.C. Those agreements allow a company like Netflix to pay a fee to a distributor, like Comcast or AT&T, for better service, when they create a lot of traffic for the network. The commission said that the condition recognized the importance of those agreements to online video service and said that it would monitor them to make sure that AT&T would not deny or impede access to its networks in anticompetitive ways.