Taiwanese smartphone maker HTC Corp stands by its decision to appeal against a U.S. trade panel's preliminary ruling in a patent dispute with Apple Inc, a top HTC executive said on Wednesday.

HTC Chief Financial Officer Winston Yung told Reuters on Wednesday that the company has not yet considered a settlement in the case, though he would not rule out any possibilities.

We are going to appeal. We are confident that we have a strong case, said Yung.

On July 15, the International Trade Commission (ITC) made a preliminary ruling that HTC infringed on two of Apple's patents.

The full commission must now rule on whether it will uphold or reverse its administrative judge's decision.

If upheld, HTC could face the possibility of not being able to sell in the U.S., which accounts for about 50 percent of its sales.

HTC is still waiting for the full opinion and analysis from the judge, Yung said. The world's No.5 smartphone maker plans to appeal after receiving and studying the material, and expects a final determination from the panel by Dec 6, he added.

Analysts have said HTC's case may get a boost after it bought U.S. smartphone technology firm S3 Graphics, which won a patent case against Apple in early July.

Smartphone technology has spawned a wealth of patent litigation. Apple also has filed complaints against Samsung Electronics.

Shares of HTC were down 0.62 percent at 0335 GMT on Wednesday, underperforming a 0.13 rise in the broader market.

The shares have been pushed as much as 30 percent below their peak in April on investor worries over faltering demand and stiff competition from Apple and South Korea's Samsung Electronics and legal challenges over patents.

(Reporting by Clare Jim and Argin Chang; Editing by Jonathan Standing)