Aimia Inc., the customer loyalty firm formerly known as Carlson Marketing, is moving its U.S. headquarters from Plymouth to Butler Square, a historic multitenant office building next to Target Center in downtown Minneapolis.

Aimia, based in Toronto, will fill the seventh floor and part of the sixth floor of the nine-story building by early next year. All 350 of the company's Plymouth employees will move to the new space.

Built in 1906, Butler Square was renovated to meet Leadership in Energy and Environmental Design (LEED) certification standards in 2009. Aimia's new space will be updated again before its move.

"We're thrilled to welcome Aimia to Butler Square," Jane Mauer, owner of Butler Properties, said in a news release. "They share our passion for sustainability and their employees will bring even more creativity and energy to downtown Minneapolis."

Aimia runs brand loyalty programs for airlines, hotels, health care and other businesses.

Kristen Leigh Painter