As part of the deal, the Lundin Family Trust also agreed increase its stake in the company from 17.7% to 19.9%.
If developed, the $2.4 billion Jadar lithium project in Western Serbia could cover 90% of Europe's current lithium needs.
Environmental campaigners are challenging the approval of a coking coal mine in northwest England.
Barrick Gold's second-quarter gold output edged up by almost 0.9% from the previous three months.
