His unexpected leap to Campbell Mithun Esty, New York, from Publicis/Bloom, where he was New York ceo, is the career equivalent of leaving a frying pan for a raging fire.
As president-ceo of CME's beleaguered New York office, Mr. Guimaraes, 49, assumes the helm of an agency facing staggering account losses and uncertain future ownership.
"He's going from one high-pressure situation to another," said one longtime industry watcher. "Campbell Mithun is in desperate shape."
Even before the agency lost Brown & Williamson Tobacco Corp.'s $40 million account last month, there were rumors circulating about a possible sale or merger by London-based parent Saatchi & Saatchi Co.
In recent weeks, executives at sister agency Backer Spielvogel Bates Worldwide, soon to be renamed Bates Worldwide, discussed absorbing CME's New York office.
Howard Liszt, Minneapolis-based CME corporate president-chief operating officer, denied that either a sale or a merger is "in the works."
Mr. Guimaraes-an experienced account handler who succeeds Tony Wainwright, 60, now agency chairman-is charged with shoring up existing clients Texaco, Thrifty Rent-A-Car, Travelers and Playboy, and adding much-needed new business to the agency, which claims billings of $150 million.
He called his move a "personal decision," one influenced by his previous associations with CME executives at Young & Rubicam.
Others familiar with Mr. Guimaraes' situation at Publicis/Bloom said, however, that the former Y&R executive had become frustrated by his inability to assume more control from Chairman Robert Bloom, whose father founded the shop in Dallas in 1952.
Mr. Guimaraes was tapped two years ago to enliven the package-goods agency, then known as Bloom FCA, and he boasted of plans to double billings within two to three years.
At an estimated $115 million, however, billings remain the same even after the recent merger with Publicis' New York office, which billed $70 million. That merger is believed to have further diluted Mr. Guimaraes' authority.
Mr. Bloom, who said he plans an informal search for a replacement, admitted he wasn't shocked the executive was unhappy, but added he was surprised by Mr. Guimaraes' sudden departure.
"I'll miss George, I like George; I don't fully understand why he's going there or why he's leaving," Mr. Bloom said. "I shook hands with George today and wished him well. He's going to need it."