The Toronto-headquartered miner said it would be resuming normal operations at the cornerstone asset, after some unionised employees downed tools earlier this week in breach of the recently ratified bargaining accord.

Local media reported workers were unhappy that part of their monthly wage was to be paid in US dollars, prompting a protest that forced the company to cut short a visit by analysts to the mine Monday.

Rosebel is forecast to produce between 280,000-295,000 ounces gold in 2018, at all-in sustaining costs of between US$990-$1,070/oz.

After market close, Iamgold also announced it had doubled its credit facility to $500 million and extended the term to 2023.

To provide further financial flexibility, the terms of the facility were also modified to provide an option to secure a further $100 million through an accordion feature, as well as to provide leasing for up to $250 million, up from $125 million.

"The doubling of our credit facility, together with the other financing options available, provide us with ample financial flexibility at a time when our organic growth projects have gained significant traction. Our balance sheet is strong with $715 million in cash, cash equivalents and short-term investments, and our long-term debt of $400 million is not due until 2025," said CFO Carol Banducci.

Iamgold shares gained 7.41% or C28c Thursday to $4.06, which gave the company a market value of $1.89 billion. The stock had last peaked at $8.20 in May.