An Ottawa employee has launched a national class action lawsuit against Nortel Networks.

The case centres around pension changes for employees with 20 or more years of service with the company.

Although Nortel employees were given 18 months notice of changes to their pensions, Nelligan O'Brien Payne -- the law firm handling the case -- says the company failed to provide employees with "reasonable notice of the changes to the pension plan."

Lawyer Steve Levitt says the employees are seeking compensation for the changes, which he says reduced the value of their pension.

The suit alleges the changes effectively decreased the value of the pension by not recognizing any pay increases after January of 2008, effectively freezing the pension.

In a statement released to CTV Ottawa, Nortel said: ". . . changes to the pension program were designed to bring the company in line with many other comparable companies, while ensuring we still offer a competitive pension plan and overall benefits program."

The company told CTV Ottawa they just became aware of the lawsuit and wouldn't offer any further comment.

For more information on the class action lawsuit, visit Nelligan O'Brien Payne's website.