Microsoft is preparing 55 legal actions worldwide against sellers on auction sites who are hawking illegal copies of the company's software.

The actions are a mix of lawsuits and criminal complaints, said Jean-Christophe Le Toquin, a Microsoft attorney for Europe, the Middle East and Africa region. Microsoft has or will file 34 actions in Europe including in the UK, Germany, France, Poland, Belgium and the Netherlands.

The company will seek prison terms for high-volume sellers and fines for less flagrant violations, Le Toquin said.

The new legal measures could take one to two years to wind through courts, depending on how quickly local police cooperate, Le Toquin said. Microsoft investigators purchased most of the fraudulent software through eBay, which hosts an estimated 50,000 pieces of pirated Microsoft software a year, he said.

Some fakes are of such high-quality that the discs and packaging are sent to a special Microsoft lab in Ireland for confirmation, Le Toquin said. Sellers attract buyers with prices well below market. "It can be from a few euros to half the price," Le Toquin said.