Trade in pirated software was worth nearly $29 billion in 2003, according to the Business Software Alliance (BSA).

The BSA is a software industry group that counts Adobe, Apple, Intel and Microsoft among its members. The body aims to assess the economic value of piracy, initiate action against pirates and to protect the patent and property of its membership.

The group acts to educate consumers and buisinesses against installing unlicensed software duplicates, and has worked with local police to clamp down on commercial pirate software traffickers.

The study found that while $80 billion in software was installed on computers worldwide last year, only $51 billion was legally purchased.

Research firm IDC was appointed by the BSA to determine piracy rates following complaints that estimates propagated by the group in the past may have been inaccurate.

IDC examined major software market segments including operating systems, consumer software and local market software to arrive at its conclusions.

Piracy rates differ between countries, betraying the clear economic impetus for companies and individuals to use pirated software, the figures show.

Vietnam, China, Ukraine, Indonesia, Zimbabwe, Russia, Algeria, Nigeria, Pakistan and Paraguay are the ten countries with the highest piracy rates, while the economically powerful US has the lowest piracy rate (22 per cent). UK piracy levels are 29 per cent of installs.

"Software piracy continues to be a major challenge for economies worldwide," said Robert Holleyman, president and CEO of BSA. "From Algeria to New Zealand, Canada to China, piracy deprives local governments of tax revenue, costs jobs throughout the technology supply chain and cripples the local, in-country software industry."