The European Commission today approved plans by CF Industries Holdings Inc. to acquire North American and certain European assets of OCI NV. However, the deal has recently been called into question due to new U.S. Department of Treasury rules pertaining corporate inversions. However, the companies said last month they are jointly evaluating options to address the rules. This evaluation includes exploring alternative structures for the combination, such as using a parent company in The Netherlands rather than one in the United Kingdom, to accommodate the requirements of the Treasury notice.