In 2002 DSM sold its petrochemical division (naphtha crackers and polyolefin plants) to SABIC of Saudi Arabia. In 2010, the agro and melamine business groups were sold to OCI Nitrogen. SABIC is located on the Chemelot campus in Sittard-Geleen, which is bounded by the Chemelot Industrial Park, one of Western Europe's biggest industrial sites. At this moment 8000 people work at Chemelot, of which 1000 are active at the Campus. The innovation and licensing division Stamicarbon of DSM was sold in 2009 to Maire Tecnimont, the parent company of an engineering, main contracting and licensing group that operates worldwide in the oil, gas & petrochemicals, power, infrastructure and civil engineering sectors. Stamicarbon is based in Sittard-Geleen. VDL Nedcar in Born (Sittard-Geleen) is the only large-scale car manufacturer in the Netherlands, currently manufacturing MINI's and BMW X1's. Other industries include Rockwool in Roermond, Océ copiers and printers manufacturers in Venlo and a paper factory in Maastricht. There are four large beer breweries in Limburg. Southern Limburg has long been one of the country's two main fruit growing areas, but over the last four decades, many fruit growing areas have been replaced by water as a result of gravel quarrying near the Meuse. Tourism is an essential sector of the economy, especially in the hilly southern part of the province. The town of Valkenburg is the main centre. In 2005, the two provincial newspapers, "De Limburger" and "Limburgs Dagblad," merged. Essential elements in Limburgian culture are   Choral singing is popular in Limburg. One of its best-known choruses is the Mastreechter Staar (Maastricht Star), which performs nationally and internationally. Every four years the World Music Contest, a competition for professional, amateur and military band sometimes called the Olympic Games of brass band music is held in Kerkrade. In 2013 and 2009 the winner in the World Concert Division was the Koninklijke Harmonie Sainte Cécile, from Eijsden (Limburg)  Also held in Kerkrade (situated on the German border) is the Schlagerfestival, a nationally broadcast event presenting singers of German-language pop music called Schlagers.