Trend Micro, the world's third-largest antivirus software maker, said Friday that computer virus attacks cost global businesses an estimated $55 billion in damages in 2003, a sum that is expected to increase this year.

Companies lost roughly $20 billion to $30 billion in 2002 from the virus attacks, up from about $13 billion in 2001, according to various industry estimates.

Read more: [URL=http://news.com.com/2100-7349_3-5142144.html?tag=nefd_top]CNet News[/URL].