NEW YORK ( The Deal) -- Marketing heavyweights Publicis SA and Omnicom Group ( OMC) on Sunday, July 28, signed off on an all-share merger that will reshape the advertising landscape, creating a Franco-American industry colossus with a market capitalization of about $35.1 billion and revenue of about $22.7 billion. The resulting Publicis Omnicom Group will be the world's largest advertising agency by both equity value and revenue. It will be 50/50 owned by the shareholders of the merger partners, with the balance achieved by special dividends of as much as $724 million for Omnicom shareholders and just under 200 million Euros ($266 million) for Publicis' owners. The combination will bring together some of the biggest names in advertising, public relations and media buying including Omnicom's agencies DDB, BBDO, TBWA and OMG as well as Publicis' Saatchi & Saatchi, Publicis Worldwide, BBH and Leo Burnett. The combination is expected to deliver "efficiencies" of about $500 million a year, split equally between improved sales opportunities and cost savings. "This is a merger that will set our new company on a path to accelerated growth, with long-term benefits for clients, employees and shareholders," Omnicom CEO John Wren said in a statement. Wren and Publicis CEO Maurice Levy will share control of the company as co-CEOs for 30 months before Levy, who is 71, becomes chairman, leaving Wren, 61, as sole CEO. Shareholders of each company will receive 50% of the combined group following distributions of special dividends to balance their contributions. Shareholders in Paris-based Publicis will receive one share in the new company for each existing share and a special dividend of 1 Euro per share. Shareholders in Omnicom, of New York, will receive 0.813 of a new share for each existing share and a payment of $2 per share. In addition, Omnicom shareholders will receive as many as two quarterly dividends of 40 cents per share ahead of the closing date. Omnicom had a market capitalization of $16.84 billion, while Publicis was worth 11.82 billion Euros ($15.69 billion) at Friday's close. The combination will see the new group leapfrog Britain's WPP to become the No.1 advertising group. WPP has a market capitalization of 15.7 billion U.K. pounds ($24 billion).