Announcing the results of its annual worldwide survey, the BSA said that software piracy cost the industry more than £8bn in 2000.
Commenting on the findings, Julia Phillpot, anti-piracy manager for Microsoft UK, said a major problem was enterprises buying counterfeit software under the impression it was genuine. "Many large organisations have been duped in this way," she claimed.
Beth Scott, vice president of the BSA in Europe, said: "Software piracy continues to rob the global marketplace of thousands of jobs, and billions in wages and tax revenues. It is also a potential barrier to innovation and product development around the world."
Some software vendors have estimated that as much as 80% of software used by small and medium-sized enterprises is pirated.
But according to Microsoft's Phillpot, "Most customers want to operate legally using genuine software. We work with customers to make sure that their licences are updated and that they have paid for the software they are using."
The UK had the lowest piracy rate in western Europe at 26% but the second highest loss at around £370m last year according to the BSA.