The unions representing Verizon workers who went out on strike last summer have asked for federal mediation through the Federal Mediation and Conciliation Service.
Last August, 45,000 Verizon workers went out on strike, remaining on the picket line for two weeks before returning to work under the terms of their old contract, which expired Aug. 6, 2011.
Negotiations have continued since then, but no agreements have been reached.
"We have no comment," said Verizon Communications Inc. spokesman Richard Young. Making the request for mediation were the Communication Workers of America and the International Brotherhood of Electrical Workers.