The European Commission has opened an in-depth probe into plans by U.S. chemical producer Huntsman to acquire the titanium dioxide assets of compatriot Rockwood Holdings.

Outlining its concerns, the Commission said it believes the deal could reduce competition in the market for sulfate-based TiO2 in the European Economic Area (EEA). The authority now has until July 22, 2014 to make a final decision.

The business under scrutiny belongs to the German company Sachtleben. To facilitate a sale, Rockwood in early 2013 bought out Finnish partner Kemira's 39% stake in the former joint venture. The assets also include a functional additives business, which was bundled into Sachtleben after the latter failed to sell separately.

According to the Commission, the TiO2 market in the EEA is worth about €3 billion. Here, it said, Huntsman and Sachtleben - the world's two leading suppliers of sulfate-based TiO2 - compete closely.

With the removal of the competition between the two companies, the remaining smaller players might not be in a position to exert a competitive influence and this, could lead to less choice for customers and potentially higher prices for the products concerned, the Brussels authority said.