Comcast, NBC promise to keep news, free TV

"Such additions might include commitments to independent programing in addition to its already stated commitment to diverse programing, maintaining access to sports programing, and ensuring that consumers still have access to their favorite shows online for minimal or no cost," said Conyers in a statement.

TRICKY APPROVAL FROM FCC?

Craig Moffett, analyst at Bernstein Research, said the key issue was Comcast-NBC's power in both distribution and programing.

"The regulators will focus on Comcast's ability to raise prices for consumers and programing fees to other distributors like satellite TV providers," he said.

The FCC's review could be trickier for Comcast and NBC than the Justice Department's review because the commissioners could force Comcast to provide content to competitors even if they disagree on the fees associated with those deals.

The companies described their deal as a vertical transaction, which means that they are not rivals but different steps in the same supply chain. U.S. antitrust regulators tend to shy away from challenging such deals on antitrust grounds.

Under the terms of the deal, Comcast would get 51 percent of a new joint venture that includes NBC Universal, valued at $30 billion, and Comcast's own cable networks, valued at $7.25 billion. GE would own the remaining 49 percent.

As payment for its stake, Comcast will contribute $6.5 billion in cash and its cable networks.

The filing, and subsequent reaction, presaged a long public battle, said Jeffrey Silva, a telecommunications expert with Medley Global Advisors, LLC.

"You can expect that public interest groups are going to ask a lot more concessions," he said. "This is just the beginning."