A jury has found that Vonage infringed on patents held by Sprint Nextel, fining the Internet telephony company $69.5 million in damages, which amounts to 5 percent of the revenue it made during the period it was using the patents.

The jury in the U.S. District Court in Kansas City, Kansas, found Vonage infringed on all six Sprint patents in question. The patents are part of Sprints voice-over-packet portfolio. Vonage used the technology to connect Internet phone calls. The jury also ordered Vonage to pay Sprint 5 percent of the revenue it makes from here on using the patented technology.

"We are extremely pleased with the verdict as it underscores the strength of our voice-over-packet portfolio and reinforces the importance of the innovations developed by our employees," Harley Ball, Sprint's vice president of intellectual property, said in a statement. "The inventions developed by the late Joseph Christie and other Sprint employees are critical to voice over packet telephony and we view the verdict as validation of the depth of our patent portfolio."

This marks the second major legal defeat for Vonage; earlier this year a federal jury found the company guilty of infringing on patents held by Verizon Communications. The court originally issued an injunction against Vonage signing up any new customers. Vonage won a stay on the injunction, though the case is still in appeal.

Vonage could face another injunction from Sprint, not surprisingly, it says it plans to appeal the jury's decision. Sharon O'Leary, Vonage's chief legal officer, told The Wall Street Journal, "We are disappointed that the jury did not recognize that our technology differs from that of Sprint's patents."