Square Deal in Hub

Partners Fred Bertino and Jamie Mambro will split off the Boston office of Square One to form a new agency with brand consultant Joe McCarthy, sources said last week.

The consultant’s McCarthy Group in Princeton, N.J., handles creative chores on the $15 million Samuel Adams beer account. Square One and Mc-Carthy have been quietly working together to develop ad concepts for the Boston Beer Co. brand, but could not move forward because of a potential conflict with Miller Lite, the showpiece client of Dallas-based Square One, sources said.

Bertino, Mambro and McCarthy may formally announce their new agency as soon as this week, sources said. Neither Bertino nor Mambro returned calls. McCarthy declined comment.

Bertino and Mambro may remain loosely affiliated with Square One and continue working on certain of that agency’s accounts. The legal terms of the buyout had not been completed as of press time last week.

Spokespersons in both Square One offices declined comment.

Fred Bertino, the former president of Hill, Holliday, Connors, Cosmopulos in Boston, left that firm in May last year to become an equity partner in Square One. He joined Mambro, formerly a top creative at Hill, Holliday who had been tapped earlier to start up Square One’s Boston office, its first outside of Dallas.

The Boston satellite has been relatively quiet since its inception with the two high-profile principals. Its only known client is Tellium, an optical equipment switching company based in Oceanport, N.J., an estimated $5-8 million account.