Top offending countries: Yugoslavia, Nigeria, Romania

A study released Thursday claims that more than 40 percent of all credit card fraud suffered by U.S. companies online is committed by overseas crooks, with orders from those five countries the most likely to be cons. The study also showed that fraud rates among sales to New Zealand, Switzerland, Japan, France and Italy are lower than fraud rates for domestic U.S. sales. Yugoslavia ranked first among high-risk countries, the study found. About 13 percent of purchases initiated from that country were fraudulent. By comparison, the fraud rate in the U.S. is about 1.7 percent, according to Cybersource Corp., which sells anti-fraud software. Many online merchants just avoid global sales all together. A full one-third of medium and large Web sites simply won't sell to international customers, according to a separate recent survey, conducted by Cybersource. International fraud rates are four times higher than domestic rates, the company says. Despite the high risk of selling overseas -- better than 1 in 10 purchases made from Romania are fraudulent, for example -- the Merchant Risk Council says electronic commerce Web sites shouldn't shy away from the potential revenue source. The council is a consortium of 1,500 companies that do business on the Web.