NEWARK, N.J.—In what is thought to be the first conviction associated with reselling hacked VoIP services, Edwin Pena in February pleaded guilty before a U.S. District Court judge in New Jersey to one count of conspiracy to commit computer hacking and wire fraud, as well as one count of wire fraud.

According to the U.S. attorney's office in Newark, N.J., Mr. Pena posed as a legitimate wholesaler of Internet-phone services, selling deeply discounted plans to customers. Mr. Pena sold more than 10 million minutes of VoIP service that had been stolen from 15 telecommunications providers, valued at $1.4 million, according to a statement from the U.S. Attorney District of New Jersey.

From November 2004 to May 2006, Mr. Pena worked with Robert Moore, a “professional hacker” in Tacoma, Wash., according to the U.S. attorney's office.

Mr. Moore hacked into the computer networks of multiple VoIP service providers and routed calls made by Mr. Pena's customers through those networks. Mr. Moore, who admitted to conspiring with Mr. Pena and pleaded guilty to federal hacking charges in March 2007, said he scanned the computer networks of unsuspecting companies and other entities in the United States and around the world, searching for vulnerable ports that he could exploit to route calls, according to Erez Liebermann, assistant U.S. attorney for the District of New Jersey.