Steel sheet piling is used mainly in the construction industry to create a retaining structure acting as a barrier or retaining wall, either on land or in river, canal or coastal building works. The Commission"s report examines the acquisition by Arcelor, of part of the UK hot rolled steel sheet piling (HRSSP) business of Corus Group plc. Arcelor was the world"s largest steel producer in 2003, created by the merger of three European companies. Corus was the world"s seventh largest steel producer in 2003, created by the merger of British Steel and a Dutch steel producer. The Commission concluded that the key event in the reduction in competition in the HRSSP sector would have been the closure of Corus"s business, which would have happened without the merger, rather than the merger itself. Given this, the Commission (by a majority of four to one) finds that the acquisition should be allowed as it is not expected to result in a substantial lessening of competition.