The (former) Swedish forestry company Stora Kopparberg would have been no. 5-9 on the list if they hadn't merged with a Finnish company in 1998. "Stora was, by one count, the oldest existing corporation or limited liability company in the world. Originally known as Stora Kopparberg, it was granted a charter from King Magnus IV of Sweden in 1347. The first share in the company is however dated already in 1288 and mining in the mountain had started possibly much earlier."
http://en.wikipedia.org/wiki/Stora_Kopparberg