PORTLAND (AP) – Forum Financial Group is being acquired for an undisclosed price by Citigroup, a move that could end up doubling or tripling Forum Financial’s work force in Maine, the companies announced Monday.

Forum Financial, based in Portland, is an 18-year-old administrator of mutual funds and other investments that services assets totaling more than $130 billion.

Citigroup, headquartered in New York, is a global financial services company with more than 200 million customer accounts worldwide. It was the No. 6 company on this year’s Fortune 500 list.

Citigroup said the acquisition includes Forum Financial’s operations in Portland, Bermuda and Warsaw, Poland. Forum Financial has more than 400 employees, including 180 to 200 in Portland, said John Keffer, founder and president of Forum Financial.

With Citigroup’s vast financial resources and distribution network, Forum Financial should be able to double or triple its work force over time, Keffer said at a press conference. He said salaries for Forum Financial employees range between $25,000 to $100,000 a year.

“This is one of the few mergers built on growth and not on cost savings,” Keffer said.

Keffer said the deal, which is expected to close by year’s end, will provide Citigroup with services it now doesn’t offer to its customers, and provide Forum Financial with greater financial resources and an established distribution network for its business.

Forum will become part of Citigroup but will continue to use the Forum Financial name for marketing purposes, Keffer said.

Gov. John Baldacci, who was at the press conference, said it is a tribute to the state’s work force that a Maine company would be purchased by a company like Citigroup. He said jobs in the financial services industry are the type that Maine wants to grow.

“This is another feather in our hat,” he said.