The Ottawa-based company says a trial jury found that the four patents in a suit against Alcatel-Lucent USA Inc., Ericsson Inc., HTC Corporation and Sony Mobile Communications had not been infringed.
Wi-LAN says certain claims in three of the four patents were found invalid. The company added that it was disappointed with the jury's decision and is reviewing its options with trial counsel.
Shares closed down more than 32 per cent, or $1.61, to $3.30 on the Toronto Stock Market.
Last year, a U.S. appeal court ruled against Wi-LAN in another dispute, affirming a lower New York State court ruling that LG Electronics did not infringe on Wi-LAN's V-Chip patent.
Wi-LAN licenses the rights to patents in its portfolio and earns money through royalty payments from companies that use the protected technology in their products and services.