(Adds CGT strike)
By Nicolás Misculin
BUENOS AIRES, July 16 (Reuters) - Port workers in Argentina's Rosario hub began an indefinite strike on Wednesday, joining grain inspectors, who walked out a day earlier and threatening exports from the world's No. 3 exporter of soybeans and corn.
Strikes and labor disputes are common in Argentina, Latin America's No. 3 economy, which has one of the world's highest inflation rates and a depreciating currency, both of which are eating into buying power. Argentine unions have hunkered down for a tough round of wage talks.
The San Lorenzo branch of the CGT, a syndicate of unions, said in a statement that from 6 p.m. local time (2100 GMT) it would be "total paralysis for an indefinite period of time in all the port terminals of the region."
Grain inspectors in Rosario, who on Wednesday at midnight began their strike in a separate labor dispute, said they would continue their strike for a second day.
"(Wage) agreements reached last year are now totally outdated, given the inflation rate," said Pablo Palacio, secretary of the Union of Grain Recipients of Argentina (Urgara) in Rosario.
Urgara has demanded a wage increase of 45 percent for its workers. Private economists estimate inflation will top 30 percent this year.
Meanwhile, crews operating port vessels have threatened to walk out on Thursday, an action that could paralyze the movement of container ships. Truck drivers have vowed to strike beginning July 21.
The latest bout of industrial action comes near the end of the harvest for soy and corn, a peak time for exports. Typically thousands of truckloads of grain reach Rosario every day, with more than $20 billion worth of grains and soy products shipped every year.
Major grains exporters operating in Argentina include Bunge , Louis Dreyfus and Cargill. (Writing by Richard Lough; Editing by Steve Orlofsky)