An HTC official said the International Trade Commission, a US trade panel that investigates patent infringement involving imported goods, would deliver its ruling on December 19.
She added that the ITC did not disclose a reason for the delay.
The International Trade Commission had earlier scheduled a ruling for Wednesday, postponed from the original date of December 6.
"It's hard to say whether the delay is good or bad because we don't know the true reason behind," said Yuanta Securities analyst Bonnie Chang.
"We hope the ruling will come as soon as possible so we can predict where the bottom is and whether there will be a settlement, and then we can have a better view of HTC's fundamentals in the coming one year."
The ruling is crucial for HTC, which has struggled with legal battles and stiff competition with Apple and Samsung Electronics Co Ltd, since it could result in a ban on the sale of HTC handsets in the United States, a market that accounts for 50 percent of the company revenue.
The suit is seen by some as a proxy for the larger fight for market share between Google Inc's Android cellphones and tablets, many of which HTC manufactures, and Apple's product line.
Korea's Samsung Electronics, which also makes Android products, is locked in similar court fights with Apple.
At 1438 GMT, shares of HTC were up 2.11 percent, beating the broader market's 0.14 percent rise. Its shares have shed 65 percent from its record high of T$1,238 hit in April.
On Tuesday, a Taiwan prosecutor said HTC had filed a criminal complaint against Citigroup Inc's Taiwan unit, alleging the broker's research contributed to a fall in HTC's share price.
