Comcast Corp.’s planned takeover of NBC Universal will draw scrutiny from Obama administration regulators who have said consolidation of U.S. media companies may thwart competition.

The deal became more likely after General Electric Co., NBC’s parent company, agreed yesterday to buy Vivendi SA’s 20 percent stake in NBC for $5.8 billion, according to two people with knowledge of the discussions. The agreement paves the way for creation of an entertainment joint venture controlled by Comcast, the biggest U.S. cable company.

The Comcast-NBC combination would be reviewed by the Federal Communications Commission and either the Federal Trade Commission or the Justice Department’s antitrust division.

“Comcast is going to face a yearlong gauntlet of regulatory and political hearings,” Craig Moffett, an analyst with Sanford C. Bernstein & Co. in New York, said in an interview.