In a formal objection on Wednesday, the Commission said it is concerned that the cooperation will lead to higher prices and fewer choices for consumers for paper used in magazines, books and advertising, among other things.
UPM and Sappi agreed this spring to merge their divisions in the area into a company that will be owned 50 percent by each side. The European Commission has until November to approve the deal or not.
UPM-Kymmene is one of Finland's largest companies.
