While any potential buyer is being kept under wraps, unnamed individuals familiar with the talks recently told Reuters that GSG may divest Colombian Natural Resources (CNR) at a loss after suffering through a significant drop in coal prices over the last few years.

The mine owner, which recently sold off its power plant holdings as well as its aluminum storage division, had also been a magnet for other problems including protests, tightened environmental regulations and issues with the Federal Reserve.

It announced last January it would halt exports due to new environmental laws, and in November 2014 a government report revealed that it was considering exiting both coal and uranium.

The company first purchased its coal holdings in 2010 and 2012 from Canadian-based Coalcorp Mining and Vale, respectively, subsequently creating CNR to oversee operations.

The Reuters report this week noted that, while it will be out of raw material production, Goldman Sachs plans to continue trading raw materials and related financial instruments.