In July 2011 , Ecolab announced a merger with Nalco Holding Company , Inc. .
In December 2011 Nalco became a wholly owned subsidiary of Ecolab   after Ecolab completed Ecolab 's US $5.4 billion acquisition .
In July 2011 , Ecolab announced a merger with Nalco Holding Company , Inc. , and in December 2011 Nalco became a wholly owned subsidiary of Ecolab Inc. after it completed its US $5.4 billion acquisition .