Allen & Gerritsen moving to Seaport District

By Johnny Diaz, Globe Staff

Allen & Gerritsen, one of the bigger ad firms in the Boston market, is moving to the city’s Seaport District.

The agency, which has called Watertown and Newton as its base for 25 years, will move its 120 person staff next month to South Boston to an area that Mayor Thomas M. Menino refers to as “the Innovation District.” Once there, the ad agency will add another 50 employees.

“Their business will benefit from collaborating in close proximity with companies such as Vertex Pharmaceuticals, AisleBuyer, Communispace and Babson College,’’ said Menino in a release. “This is great news for Boston.”

Andrew Graff, the agency’s chief executive officer, said the new location will help his staff attract more clients in the Boston business community.

“Boston has a history of being on the forefront of invention and culture,’’ said Graff in a release. “Allen & Gerritsen will play a major part in Boston’s economic future as a world class city of innovation.”

The move comes just as industry magazine Advertising Agency named Allen & Gerritsen as the top place to work among advertising agencies.

The agency’s client roster includes Boston brands such as the Boston Celtics, Bright Horizons Family Solutions, and the chain of Ninety Nine Restaurants. Last year, the agency developed a popular TV and radio campaign for National Public Radio affiliate WBUR-FM 90.9 to help the station differentiate it from another Boston NPR affiliate, WGBH-FM 89.7.