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 Tuesday by the Business Software Alliance (BSA).

Global losses from software piracy, however, rose by US$1.6 billion, to US$34 billion, according to BSA, a trade group focused on fighting the unauthorized use of software.

Some economists have questioned the loss estimates in the annual study, prepared by IDC. The loss 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 chief executive officer, 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, 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, US$6.9 billion. China saw the second highest losses at US$3.9 billion with a piracy rate of 86 percent, followed by France with losses of US$3.2 billion and a piracy rate of 47 percent, according to the study.

The four countries with the largest drop in their piracy rates in the last year were Ukraine, down 6 percentage points, and China, Russia and Morocco, all down 4 percentage points, the study said.

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.