A US jury ordered Dutch electronics giant Philips to pay $466.8 million to the American corporation Masimo for violating two medical device patents.
The eight members of the Delaware jury gave their verdict on Wednesday, after a two-week trial, which came after California-based Masimo had filed a complaint in February 2009.
Jurors also found that Masimo had not infringed a Philips patent, as the Dutch firm had claimed.
"We are very disappointed in the verdict and will appeal this decision of the jury," Philips spokesman Steve Klink said in a statement.
"We remain convinced that Philips has not infringed any valid, enforceable patent claims of the two asserted Masimo patents."
AFP could not immediately reach a Masimo spokesperson for comment. The case involved patents related to pulse oximetry, a non-invasive technique of determining oxygen levels in blood.
Masimo shares closed 12.88 percent higher in New York, at $24.02.