The U.S. Court of Appeals for the Federal Circuit has denied Vonage's request that a patent infringement ruling against it be vacated and the case sent back to the lower court for a retrial. The company can, however, reference the matter in its appeal brief, due next Wednesday.

Vonage's request followed a ruling Monday by the U.S. Supreme Court that called into question the patentability of "obvious" inventions. Verizon sued the company for infringing on its voice over IP patents, but Vonage claims the patents should not be considered valid.

The denial for a retrial is a minor blow to Vonage's case, but the company reiterated Thursday that it has no impact on the overall appeal - which it expects to win. Verizon officials made no comment on the decision.

"Vonage continues to believe the original verdict was based on erroneous claim construction - meaning the patents in this case were defined in an overly broad and legally unprecedented way," the company said in a statement.

Verizon sued Vonage in June 2006, accusing the fledgling voice over IP firm of knowingly infringing on patents related to functionality such as call forwarding and fraud detection. A jury agreed with Verizon in early March, awarding the company damages of $58 million in addition to a 5.5 percent royalty on all future Vonage sales.

An oral hearing regarding the appeal is scheduled for June 25. If Vonage loses the appeal, it could be hit with a permanent injunction that would bar it from using Verizon's technology, forcing the company to settle or potentially face a shutdown of its Internet telephone service.