Japan Tobacco Inc (2914.T) is in the final stages of talks to buy Reynolds American Inc’s (RAI.N) Sante Fe Natural Tobacco unit for about $5 billion, aiming to reach an agreement this week, the Nikkei business daily reported on Tuesday. Officials at Japan Tobacco (JT) and Reynolds American were not immediately available for comment. With the purchase of Sante Fe, JT hopes to gain marketing rights for the Natural American Spirit brand, which is sold in the United States, Japan and Europe, the Nikkei said.