U.S. drugmaker Merck & Co Inc's $41.1 billion takeover of smaller rival Schering-Plough Corp won approval from European Union antitrust regulators on Friday.

The takeover, structured by Merck as a reverse merger, followed a long-standing joint venture between Merck and Schering-Plough that sells the cholesterol fighters Vytorin and Zetia.

The proposed transaction would not significantly impede effective competition in the European economic area or any substantial part of it, the European Commission, executive arm of the 27-country EU, said in a statement.

Merck has agreed to sell its half of the Merial animal health business to Sanofi-Aventis, its French partner in that joint venture, for $4 billion in order to meet antitrust requirements for the Schering-Plough takeover.

The deal still needs U.S. antitrust approval. The companies continue to expect the transaction to close in the fourth quarter.

Merck has said it hopes cost cuts from the merger and a number of promising products from Schering-Plough will improve its profit outlook.

The merged companies will cut 15 percent of their combined workforce, with most job losses to take place outside the United States.

(Reporting by Foo Yun Chee and Lewis Krauskopf in New York; Editing by Dale Hudson, Dave Zimmerman)