The Swiss pharmaceutical group, Roche, has been ordered to pay $20 million (SFr33 million) to the United States biotechnology group, Chiron.
The decision follows a ruling by the European Patent Office that Roche infringed Chiron's licence for sales related to its "HIV patent 150", which is used in clinical diagnostic and blood screening products
The fine covers sales prior to October 2000, after which Roche and Chiron had signed a broad patent licence deal for nucleic acid probe-based clinical diagnostics for HIV-1.
The German companies Bayer and Organon Teknika will also be paying compensation to Chiron for infringing its licence.
The US group's patent expires in 2005.
swissinfo with agencies