Argentina soyoil shipments were slowed on Tuesday by the start of a wage strike by a union representing 20 percent of the country's crushing workers, while the powerful CGT dock-workers union debated whether to join work stoppage.
Argentina is being racked by wage negotiations driven by inflation estimated by private economists at 25 to 30 percent.
The country is the world's No. 1 exporter of soyoil, used in the international biofuels industry, and soymeal livestock feed. It is also the No. 3 supplier of raw soybeans.
Soy is a key source of protein for cattle, chickens and pigs as world food demand rises and diets in Asia shift from rice toward meat. If the soyoil workers strike spreads to other unions representing stevedores at Argentina's key grains hub of Rosario, all farm exports could be affected, putting upward pressure on world food prices.
The strike by the Soyoil Workers Federation comes smack in the middle of what promises to be a record Argentine soy harvest. The CGT labor federation, which represents dock workers and has the power to paralyze Argentina's ports, is set to vote Tuesday night on whether to join the crushers strike.
The soyoil federation met with representatives of the CIARA-CEC export company chamber on Monday at the Labor Ministry in Buenos Aires, but were unable to reach a deal.
The workers are asking for wage hikes of 42 to 48 percent.
"The federation has never been willing to negotiate these percentages," CIARA-CEC said in a statement.
The union issued a statement of its own, accusing CIARA-CEC of not responding to its wage proposal, and promising to continue the strike "as long as it takes".
A representative for the San Lorenzo Soyoil Workers, which represents 80 percent of Argentina's soyoil crushers and is based in the country's main grains hub Rosario, said it has until May 27 to negotiate a wage deal and plans no strikes.
The CGT umbrella labor organization, which represents truck drivers as well as dock workers, may walk off the job as early as Tuesday night.
"We will decide tonight whether to join the Soyoil Federation's strike," said Edgardo Quiroga, spokesman for the CGT, which is also in tough wage talks.
Argentina's 2014/15 crop is expected at a record high 60 million tonnes, the Buenos Aires Grains Exchange said last week, thanks to smooth harvesting and unexpectedly high yields.
(Reporting by Hugh Bronstein)