(Adds details of lawsuit, background, byline)
Jan 25 (Reuters) - Gene testing company Illumina on Thursday won a $26.7 million jury verdict in a U.S. lawsuit accusing rival Ariosa Diagnostics, a subsidiary of Roche Holdings AG, of using patented prenatal testing technology without authorization.
A federal jury in San Francisco said Ariosa's Harmony non-invasive prenatal test kits infringed on two Illumina patents.
Illumina and Ariosa compete in the growing market for non-invasive prenatal tests, which screen for chromosomal conditions like Down syndrome.
San Diego, California-based Illumina had sought more than $100 million in damages.
The jury rejected a counterclaim by Ariosa that Illumina had breached a contract between the companies by bringing the lawsuit. Ariosa had sought $88 million in damages from Illumina on that counterclaim.
Illumina and Ariosa did not immediately respond to requests for comment.
Roche acquired San Jose, California-based Ariosa for $625 million in January 2015.
(Reporting by Jan Wolfe; Editing by Cynthia Osterman and Richard Chang)