The contract expires Oct. 6 between the company and Communications Workers of America District 7 representing 13,000 employees across 13 states.
The union approved a strike in 2008, though a work stoppage wasn't ordered.
According to the Denver Post, both sides are still far apart on a couple of key issues, including health care costs.
Meetings have been held over the past month in Denver between the Monroe, La., based company and the union.
(Copyright 2012 by The Associated Press. All Rights Reserved.)