The company requested the Labor Ministry convene an arbitration tribunal to solve a dispute with its largest workers' union and lift a more than 70-day strike.
Acuña and her family claim the company used violence and threats to try to evict her from her home and so make way for its $5 billion gold and copper Conga project.
Move would seek to secure approval for its friendly merger with smaller rival Agrium, creating the world’s largest potash miner worth about $36 billion.
Vancouver-based producer rises 33% after Supreme Court of the central American nation reinstates operating licence for world's third largest silver mine.
While production in August was below normal due to the ongoing disruptions to the company’s operations, Gran Colombia expects to meet its annual production guidance for 2017 of 150,000 to 160,000 ounces of gold.