SUNTRACS, the largest union representing workers on the Panama Canal expansion project, said it planned to declare a strike to press the Grupo Unidos por el Canal, or GUPC, consortium for a pay increase.
Negotiations with the government and the consortium have gone on for two months, with no agreement reached, SUNTRACS secretary-general Saul Mendez told EFE.
"We still don't have an exact date, but it could happen at any time," Mendez said, referring to the strike.
The 6,000 construction workers will go on strike unless they get a pay increase of more than 8 percent that should be retroactive to July 1 under the terms of the collective bargaining agreement with the Panamanian Construction Association, Mendez said.
The GUPC consortium's members are Spain's Sacyr, Italy's Impregilo, Belgium's Jan de Nul and Panama's CUSA.
The Panama Canal expansion project, which was 91.3 percent complete as of June 30, is expected to be finished in six months, the GUPC said.
The expanded sections of the waterway are expected to open to shipping in April 2016.
Work on the $5.25 billion project started in 2007.
The Panama Canal currently handles about 6 percent of world trade.
La Prensa