Twin Cities tech start-up Bannerflow said it has been acquired by Swedish software firm Nordic Factory for an undisclosed amount.

The start-up sold software services that helped ad and design businesses show banner ads to clients. Due to the acquisition, Bannerflow said its service will be shut down and its customers will be integrated into Nordic Factory.

"This is a bittersweet moment for us," said Tom Buchok, who co-founded Bannerflow with entrepreneur Mike Bollinger in 2008. "While we're sad to see Bannerflow change hands, we are excited we were able to create a service that so many people found valuable."

Nordic Factory has its own product called "BannerFlow" which produces online banner ads. The company purchased Bannerflow because it wants to expand its U.S. business, said Nordic's business manager Daniel Fahlen in an e-mail.

Bannerflow in Minnesota was operated by just two people, Buchok and Bollinger.