Caribou Coffee has its company headquarters in Brooklyn Center, Minn., and runs 610 coffee shops in 22 states and 10 countries, the St. Paul, Minn., Pioneer Press reported Tuesday.
The investment firm called JAB is known for purchasing luxury brands, such as Zagliani handbags and Calvin Klein fragrances, the newspaper reported.
JAB also bought Peet's Coffee and Tea for about $1 billion this fall.
"Caribou has a fantastic brand and unique culture, and fits perfectly with JAB's investment philosophy of investing in premium and unique brands in attractive growth categories like coffee," said JAB Chairman Bart Becht in a statement.
The deal, which requires shareholder approval, amounts to $16 per share, a 30 percent premium over the company's closing price on Friday.
But news of the deal pushed share values above $16 and three law firms said they would investigate the deal on behalf of shareholders.
Caribou President and Chief Executive Officer Mike Tattersfield said the deal could help the brand to grow.
"We anticipate the next chapter in Caribou's journey will be filled with tremendous opportunities to grow this great brand, with new ownership," Tattersfield said.