The Federal Trade Commission cleared the way Thursday for Schering-Plough‘s $41.1 billion acquisition of Merck & Co., but required both companies to make significant divestures.

Under the terms of the FTC’s consent order, Merck must sell its interest in Merial Limited, an animal health joint venture with Sanofi-Aventis, and Schering Plough must sell its assets related to drugs that treat nausea and vomiting in humans.