Robert Gannicott, the man who co-founded the company now known as Dominion Diamond Corporation, is exiting his role as company chairman.

Dominion owns a majority stake in the Ekati diamond mine, located 300 kilometres northeast of Yellowknife, and a minority stake in the neighbouring Diavik diamond mine. 

Gannicott, who has sat on Dominion's board for 12 years, recently returned to the company after an eight month medical leave of absence. Upon his return, he ceded the position of chief executive officer to Brendan Bell, a former N.W.T. minister of Industry, Tourism and Investment. 

"Both the company and I have faced certain changes recently," Gannicott said in a Dominion Diamond statement released Wednesday. 

Robert Gannicott

Robert Gannicott cited health reasons for his departure. He had already taken a medical leave of absence from his former post as CEO of Dominion Diamond Corporation. (Dominion Diamond Corporation)

"For the company, these represent opportunities but in my case they represent medical challenges."

Dominion paid Gannicott $7.2 million US (after taxes) when he gave up his CEO position, a move Bell defended during an earnings call last year. Gannicott received stock benefits as a part of that package, according to regulatory filings.

"Look he's been pivotal, he built the company, he effectively founded this company. And that's the rationale for
the payment to Bob," said Bell.

Gannicott's replacement used to run De Beers Canada 

Gannicott's eventual replacement as chairman will be Jim Gowans, a former DeBeers Canada CEO and most recently the co-president of Barrick Gold, the world's largest gold mining company. 

According to the release, Dominion is hoping to appoint Gowans as chairman by April 30, 2016.

Dominion also announced the appointment of Josef Vejvoda, a former portfolio manager at a Toronto investment fund, to its board. 

A group of shareholders proposed the appointment of Vejvoda, though it is unclear if it's the same group that recently met with Dominion to discuss their unhappiness with how the company is being run

The board shakeups come at a busy time for Dominion.

Later this month, the Mackenzie Valley Environmental Impact Review Board is expected to release its report on the potential environmental impacts of the Jay project, an expansion of the Ekati mine that Dominion says will help keep Ekati in production until 2033. That report is a key step toward Dominion receiving the permits to start construction on Jay.   

Contract renegotiation talks with around 500 Ekati workers will finally resume after a months-long dispute kept Dominion and the Union of Northern Workers away from the negotiation table since last summer. The contract expired in August 2014.