Mr. Sheehan, 42, replaced Jack Connors, a founding partner and chairman of the agency. Mr. Connors, who will retain his chairmanship, said relinquishing the role of CEO will allow him to spend more time with favorite clients and more involved with Interpublic, where he is chairman of its operating committee.
Interpublic, the world's No. 2 agency holding company, has been hampered by sub-par profitability that it blames largely on high costs, particularly at one of its networks, McCann-Erickson Worldwide. Interpublic is also embroiled in accounting irregularities and an related Securities and Exchange Commission investigation. Earlier this year, Mr. Connors agreed to remain at the helm of Hill Holliday until at least 2008.
A first for the agency
Mr. Sheehan is the agency's first non-founding partner to hold the CEO post. In January 2002, he was named president of all U.S. operations, a role he will retain. In addition to its headquarters in Boston, the agency has offices in San Francisco and New York.
Mr. Sheehan, who will continue to report to Mr. Connors, was instrumental in bringing in new business, including Anheuser-Busch Cos., for which the agency produced a much talked-about Super Bowl spot of Clydesdales genuflecting at the post Sept. 11, 2001-New York skyline.
"While this is clearly a promotion for Mike, it's more a reflection of the reality that Mike has been serving in this capacity for some time," Mr. Connors said. "Since naming Mike president, I feel the agency has become a better one under the energetic and intellectual leadership that he has brought to Hill Holliday."