Thirty-five percent of the packaged software installed on PCs worldwide in 2005 was pirated, the same percentage as in 2004, according to a study released today by the BSA (Business Software Alliance).

Global losses from software piracy, however, rose by $1.6bn (about £850m), to $34bn (£18 billion), according to the BSA, a trade group focused on fighting the unauthorised use of software.

Some economists have questioned the loss estimates in the annual study, prepared by IDC. The estimates reflect the total price users would have paid for legitimate versions of the pirated software, but in some cases, users may have decided not to use the software if they would have had to pay for it, Robert Holleyman, BSA's president and CEO, said recently. Holleyman applauded progress by some countries, but said much more needs to be done.

While the amount of global piracy has not gone down, some countries, including China, Russia and India, have made progress, the BSA said.

The US had the lowest piracy rate of all countries studied, 21 percent, but because of the size of the software market there, it posted the highest losses, $6.9bn (£3.7bn). China saw the second highest losses at $3.9bn (£2.1bn) with a piracy rate of 86 percent, followed by France with losses of $3.2bn (£1.7bn) and a piracy rate of 47 percent, according to the study. The UK came in fifth with $1.8bn (£1bn) in losses.

The four countries with the largest drop in their piracy rates in the last year were Ukraine, down six percent, and China, Russia and Morocco, all down four percent, the study found.

The countries with the highest piracy rates were Vietnam and Zimbabwe at 90 percent each, Indonesia at 87 percent, and China and Pakistan with 86 percent each. In addition to the US, countries with the lowest piracy rates included New Zealand, Austria and Finland.