Chemical transportation company Stolt-Nielsen SA said it is buying three used tanker ships for about $40 million. The company said its wholly owned subsidiary, Stolt-Nielsen Transportation Group, has exercised an option to purchase the tankers, currently on charter, from Montana Ship Holding AS. According to Stolt-Nielsen, it chartered the ships in December 2001 with an option to buy at any time. The company said the three ships are to be converted at a cost of $7.5 million to meet new safety regulations that will take effect Jan. 1 next year. (Source: http://news.moneycentral.msn.com/)