Shares in smartphone maker HTC closed almost four percent down on Monday after Friday’s ruling against it from a US trade panel on a patent case brought by Apple.
If the preliminary decision is ratified by a full panel, HTC could face a huge compensation payout to Apple.
HTC, which uses Google’s Android operating system, said it would appeal against the ruling which is just one of a number of similar complaints between smartphone makers.
The sell-off came despite HTC announcing a share buyback over the weekend following the ruling in an attempt to support its shares.
If the ruling by the US International Trade Commission stands, HTC could be banned from selling some of its phones in the US. A final decision is due in early December.
Apple is also in dispute with Samsung and Motorola on similar cases and HTC has brought patent infringement cases against Apple.