PORTLAND, Maine — A firm that buys and defends intellectual property rights has sued FairPoint Communications and two other companies, alleging violations of certain network communications technologies developed by the bankrupt multinational telecom firm Nortel.

The lawsuit is part of the fallout from a $4.5 billion purchase of Nortel intellectual property by a consortium of technology giants, including Apple and Microsoft, organized as Rockstar Consortium.

The Virginia-based Spherix Inc. filed the infringement lawsuits Friday, related to methods for formatting data frames on devices connected through a virtual local area network.

Spherix claims FairPoint has used those methods as part of its service offerings to commercial customers, an area where FairPoint’s business has shown the strongest growth as its landline phone service declines in users and revenue.

FairPoint spokeswoman Angelynne Beaudry said the company does not comment on active or pending lawsuits and the company has not yet submitted a response to the Spherix complaint, filed April 26 in U.S. District Court in Delaware.

In a news release, Spherix said that it acquired a portion of the patent portfolio purchased by Rockstar, which it now seeks to protect through litigation and licensing efforts.

“We previously announced to shareholders that we intended to expand our monetization efforts, and these suits are an early part of that effort,” said Spherix CEO Anthony Hayes in a news release.

He added that Spherix intends to seek licensing agreements with subjects of its lawsuits.

Spherix announced in 2014 that it acquired a batch of more than 100 patents held by Rockstar, covering things such as “the way traffic, video and voice data is carried over public and private networks,” according to a company statement announcing that purchase.

The portfolio of patents from Nortel covered a wide range of communications technologies now fundamental to many wireless technologies.

Wired reported that about 2,000 of the former Nortel’s patents were split between members of the Rockstar Consortium, while the other 4,000 were left with the new company in order to enforce and pursue licensing deals.

Nortel, a Montreal-based telecom giant founded in the late 1800s, employed about 90,000 people and was Canada’s largest company during its peak in 1990 and 2000, before filing for Chapter 11 bankruptcy in 2009.

Darren Fishell

Darren is a Portland-based reporter for the Bangor Daily News writing about the Maine economy and business. He's interested in putting economic data in context and finding the stories behind the numbers.