A strike by one of the labor unions at Barrick Gold Corp's  Veladero mine in Argentina, the site of three cyanide solution spills in 18 months, has ended, the company said on Monday.

Formal talks have started with the union to address their concerns, Barrick said in a statement. It did not say what these concerns were.

The AOMA union could not immediately be reached for comment.

The strike, which began early on Sunday, was the latest blow to hit the mine, one of Barrick's five core operations.

Leaching activities at Veladero have been restricted since March 29 when a pipe carrying cyanide solution used for processing gold from ore failed at the mine's heap leach facility.

Construction in the heap leach valley that is needed for full operations to resume at the mine was not affected by the work stoppage, Barrick said. It said it still expects to resume normal leaching activities in the second half of June.

The government of Argentina's San Juan province, where Veladero is located, said earlier this month that it had approved a plan for improving safety following the facility's most recent cyanide solution spill.

Barrick's stock was little changed, up five cents at $22.08 on the Toronto Stock Exchange.

Barrick, the world's biggest gold producer, agreed in April to sell 50 per cent of Veladero to China's Shandong Gold Mining Co Ltd for US$960 million.