(Updates Cerrejon response)
BOGOTA, March 3 (Reuters) - Union workers at Colombia's largest coal mine, Cerrejon, have voted in favor of a strike, the union said on Thursday, in a dispute with the company over wages and benefits.
A strike at the Cerrejon mine, which produces 32 million tonnes of coal a year, or 37 percent of Colombia's total output, would come at an inopportune time for the country, which is experiencing a commodity-related economic slowdown.
"The workers voted to declare the strike," Sintracarbon union leader Jairo Quiroz said in a phone interview. "In the next 10 days, we will decide the start date."
Cerrejon is a joint venture between Australia-based BHP Billiton Ltd , London- and Johannesburg-based Anglo American Plc and Swiss-based Glencore Xstrata . It has been producing coal in Colombia since the mid-1980s under a concession that runs until 2033.
Colombia is the world's fifth largest coal exporter. The country's output fell 3.5 percent in 2015 to 85.5 million tonnes.
The vote came after a 40-day period of direct negotiations ended without an agreement. The union and the company will meet again on Friday, Quiroz said.
A representative from Cerrejon said the vote did not necessarily mean a strike would take place and that it is important the two sides continue the negotiations during the 10-day period the union has to declare a start time.
The union represents 4,200 of the 10,000 workers at the mine, located in La Guajira province in northern Colombia.
The vast majority of union members who voted were in favor of the action, Sintracarbon said on Twitter, with 3,428 voting to strike. Twenty-seven members favored taking the matter to a tribunal and 33 were null votes.
Cerrejon has offered a 6.77 percent pay increase, in line with last year's inflation rate, while workers want a 10.1 percent raise, Quiroz told Reuters in an interview last week.
They also want improvements in education, health and housing.
Production at Cerrejon fell by 1.48 percent last year, while exports were down 2.33 percent.
The last strike at Cerrejon took place in February 2013 and lasted 32 days. (Reporting by Luis Jaime Acosta and Julia Symmes Cobb; Editing by Peter Cooney and Chris Reese)