Dominion, the world's third-biggest diamond producer by value, said it had hired executive recruiting firm Korn Ferry to find a replacement.

Bell, who has also stepped down from Dominion's board, has agreed to stay on as CEO until June 30 to ensure a smooth transition.

Dominion announced in November that it was moving its head office to Calgary from Yellowknife in Canada's Northwest Territories, where its diamond operations are based, to cut costs.

"For personal reasons, however, this is not the right move for my family," Bell said in a statement.

Shares of Dominion, which operates the Ekati Diamond Mine and owns 40 percent of the Diavik Diamond Mine, were down 0.7 percent at C$13.16.

The company faced a shareholder revolt 13 months ago from an investor group angry at its falling share price.

(Reporting by Nicole Mordant in Vancouver; Editing by Lisa Von Ahn)