Omnicom Group and Interpublic Group are one step closer to creating the world’s largest advertising and marketing agency after clearing a crucial U.K. regulatory hurdle.

The Competition and Markets Authority said Wednesday that the impending $13 billion merger would not be referred to an in-depth phase-two probe. The avoidance of this step puts the merger between the two companies on track to close within the next few months. 

This follows the Federal Trade Commission’s approval of the merger, which occurred in June. In signaling the green light, the FTC also issued a consent decree barring the combined entity from engaging in politically motivated boycotts. 

Upon clearing the FTC’s review, Omnicom and IPG issued a joint statement from CEO John Wren, who said the companies were “delighted” that their deal had cleared “this significant regulatory hurdle” and called it an important step toward “creating a new era” of marketing solutions. 

IPG CEO Philippe Krakowsky added at the time that the merger would combine “deep pools of talent, complementary capabilities, and geographic strengths” to “meet the evolving needs of clients in a consumer and media landscape being transformed by technology and data.”

The European Union is one of the remaining governing bodies that has not yet approved the merger. During an investor call in July, Wren noted that Omnicom had earned 13 out of 18 regulatory approvals. 

Omnicom reported revenue of $4 billion during the second quarter of 2025 and forecasted organic revenue growth between 2.5% and 4.5% for the remaining half of the year.