German drugmaker Merck secured EU regulatory approval on Wednesday for its takeover of U.S. biotech tool maker Millipore, marking a diversification away from the pharmaceuticals business.

Merck, maker of the multiple sclerosis drug Rebif and owner of the rights to cancer drug Erbitux in Europe, unveiled the $6 billion deal in March. Analysts had said the transaction made sense as Merck's liquid crystals unit, its main cash cow, faces increasing competition from Asian rivals.

"Although the parties are both active in the life science business, they focus on different markets," the European Commission said in a statement.

The two groups' activities overlap modestly in the market for air monitoring systems, but their combined market shares remained relatively low, the Commission said.

Given the presence of strong competitors, the Commission concluded that the transaction did not raise competition concerns. Millipore makes filters and purifiers for laboratory water and other materials used in making biotechnology drugs.

Read CHEManager Europe's interview with Merck Chairman Dr. Karl-Ludwig Kley here.