NEW YORK — Shareholders have “overwhelmingly approved” Omnicom’s acquisition of  Interpublic, greenlighting the creation of what will likely be the world’s largest marketing services group.

Shareholders from both Omnicom and IPG approved the deal in special meetings held today. The companies remain on track to complete the transaction in the second half of 2025 subject to regulatory approval, Omnicom said.

"We are very pleased to reach this important milestone. The strong support of our stockholders confirms the compelling value proposition of the transaction and the leading-edge services, products and platforms it will create for our people and clients," said Omnicom chairman and CEO John Wren.

Based on data from the last two years, it is likely that the merger, which was announced in December, will take the two holding companies past Publicis Groupe and WPP to become the world's largest marketing services group.

In terms of public relations, Omnicom owns top 20 firms FleishmanHillard and Ketchum, as well as smaller operations such as Porter Novelli and MMC, as well as several public affairs brands. Interpublic is parent to The Weber Shandwick Collective (which includes Current Global) and Golin.

It is unclear how the merger will impact these public relations brands, although it appears there are no immediate plans for restructuring. When first announced, Omnicom said that that transaction is expected to generate annual cost synergies of $750 million but it is unclear where those savings will come from.

Under the terms of the agreement, Interpublic shareholders will receive 0.344 Omnicom shares for each share of Interpublic common stock they own. Following the close of the transaction, Omnicom shareholders will own 60.6% of the combined company and Interpublic shareholders will own 39.4%.

The new Omnicom will have more than 100,000 employees and operations spanning media, precision marketing, CRM, data, digital commerce, advertising, healthcare, public relations and branding.

"With an overwhelming majority voting in favor of the transaction, it is clear that our stockholders see the immense opportunity of Interpublic joining forces with Omnicom," said Interpublic CEO Philippe Krakowsky. "Their approval reflects the tremendous potential we have to create one of the most dynamic, client-focused, and forward-leaning organizations in our industry that will deliver significant shareholder value for years to come."