A U.S. appeals court on Wednesday upheld a verdict that Vonage Holdings Corp. infringed two patents held by Verizon Communications Inc and also reaffirmed an order barring Vonage from using the Internet phone call technologies involved.

The U.S. Court of Appeals for the Federal Circuit affirmed an injunction issued by a lower court judge earlier this year with regard to two of three Verizon patents, while reversing the judge’s interpretation of a third patent in the case.

The appeals court sent the case back to the district court for further proceedings on the third patent and a new calculation of damages and royalties awarded to Verizon.

The decision was a further blow to Vonage, coming a day after a U.S. jury found it had infringed patents owned by Sprint Nextel Corp.

Vonage shares were halted soon after trading began Wednesday on the New York Stock Exchange after falling 26 cents, or 20 percent, to $1.04. At that price they have fallen 94 percent from the company’s initial public offering at $17 per share in May 2006.

A Vonage spokeswoman confirmed the court upheld two of the three verdicts in the Verizon case but declined to comment further, saying the company was still preparing a statement.