UnitedHealth Group Inc., Minnetonka, declared a quarterly dividend of 50 cents per share, payable Dec. 15 to shareholders of record on Dec. 4.

Mergers and acquisitions

3M Co., Maplewood, completed the sale of its remaining global library systems business assets to a fund advised by One Equity Partners Capital Advisors LP. Earlier 3M Co. had sold its North American library systems business assets to One Equity Partners.

New Business

Donaldson Co. Inc., Bloomington, announced that it has opened two new distribution centers in Bogota and Cartagena, Colombia, and a new manufacturing plant in Skarbimierz, Poland. The additions mean Donaldson will have six distribution centers in Latin America and its third plant serving Eastern and Central Europe.