Sept. 21 (Bloomberg) -- Vonage Holdings Corp. built its Internet telephone network using Sprint Nextel Corp. technology and should be forced to pay more than $100 million, Sprint's lawyer told jurors in closing arguments at a patent trial.

``These patents are core to Vonage; these patents are core to what they do,'' B. Trent Webb of Shook Hardy & Bacon told the jury today. ``This technology allows them to exist.''

Sprint, the third-largest U.S. phone company, sued Vonage in 2005, seeking cash compensation and a court order to stop Vonage from using six inventions. After a three-week trial that started Sept. 4, the panel of five women and three men began deliberations today in federal court in Kansas City, Kansas.

Sprint, based in Reston, Virginia, is entitled to a royalty of 7 percent, Webb said. Based on Vonage's historical revenue, damages total $97 million, plus interest, he said.

Vonage, based in Holmdel, New Jersey, claims it isn't violating Sprint's patents. Vonage is contesting the validity of all six patents, arguing they shouldn't have been issued. The disputed technology helps connect Internet phone calls.

``These patents are invalid. We don't owe them a dime,'' Vonage lawyer Louis Jameson told the jury in his closing argument.

Jameson scoffed at Sprint's demand for $97 million in damages. ``Folks, that is nuts,'' he said. ``That is a huge amount of money for a startup company.''

Verizon Loss

U.S. District Judge John Lungstrum instructed the jurors on the law prior to today's closing arguments. Last month, Lungstrum denied a pretrial motion by Vonage for a ruling that at least some of the Sprint patents weren't violated.

The jury left for the weekend without reaching a verdict and will return to continue deliberations on Sept. 24.

Vonage lost a patent-infringement case to New York-based Verizon Communications Inc. this year and was ordered to pay more than $58 million in damages and a 5.5 percent royalty on future revenue. Vonage appealed the patent loss to Verizon, and a decision is pending.

Sprint Corp. was based in Overland Park, Kansas, until it merged with Nextel Communications Inc. in 2005.

The case is Sprint Communications Co. v. Vonage Holdings Corp., 05-2433, U.S. District Court, District of Kansas (Kansas City).

To contact the reporter on this story: Jeff St.Onge in U.S. District Court in Kansas City, Kansas, at jstonge@bloomberg.net

Last Updated: September 21, 2007 20:00 EDT