The 2% rise over 2008 figures was due to more sales of PCs in emerging markets, the Business Software Alliance said in its annual global study of software piracy, prepared by IDC.
BSA CEO Robert Holleyman said, "Given the economy, 2009 piracy rates are better than we expected."
He called on governments in emerging economies to act harder and faster to deter piracy.
Holleyman said a 43% piracy rate meant that for every $100 worth of legitimate software sold in 2009, $75 worth of unlicensed software also made its way into the market.
"This underscores the increasing sophistication of pirates and the urgent need for stronger anti-piracy efforts," he said.
IDC's chief research officer John Gantz said cutting software piracy by just 10 percentage points for the next four years would create nearly 500,000 new jobs and pump $140bn into ailing economies.
The US piracy rate was 20%, the lowest in the world, but cost $8.4bn in 2009, IDC found after looking at 182 discrete sets of data from 111 countries.
Piracy rates increased in 19 countries, up from 16 in 2008. This was due to growth in the consumer PC base and in emerging markets, IDC said.
PC shipments to consumers rose 17% in 2009, while shipments to businesses, governments and schools dropped 15%. Brazil, India and China accounted for 86% of the growth in PC shipments worldwide.
China saw the largest increase in the commercial value of pirated software of any country, growing $900m to $7.6bn.
India, Chile and Canada each cut their piracy rates by 3%.
This story was first published by Computer Weekly