But current CEO Burt Manning, 64, warns against viewing Mr. Jones as a boardroom youngster.
"Chris has had excellent preparation for ever-increasing responsibility and authority," Mr. Manning said. "He has made tremendous contributions to major, major client businesses around the world."
Mr. Manning made it clear Mr. Jones is now in line to take his place, saying he anticipates the next promotion within two years.
Mr. Jones will move to New York from London, where his latest position was exec VP-managing director, multinational accounts. The clients that have received most of his attention include Unilever, Kellogg Co. and DeBeers Consolidated Mines.
Mr. Jones' experience with multinational clients clearly was a factor in his promotion. But he cautioned that building and strengthening multinational accounts is only a part of JWT's strategic plan.
"It's a very important area, but not the only important area. But it's true that if we don't get that right, we don't get a chance to get the other parts right," he said.
The other co-president is Peter Schweitzer, based in Detroit, who had held the title of president until Mr. Jones' promotion.
His first agency job was at Saatchi & Saatchi Advertising, London, where he worked on Procter & Gamble Co. accounts, among others. He joined JWT in 1984.
JWT was the world's third-largest agency brand in 1994, with $881 million in gross income, trailing Dentsu and McCann-Erickson Worldwide.