However, the company’s aggregate sales of rough and polished diamonds in the quarter ended 31 March 2013 were $1.22bn, an increase of 5% from the first quarter of fiscal 2012.

The company attributed the growth in sales to the increased demand on the rough and polished diamonds market in the quarter.

"Having insignificantly adjusted rough diamond prices in the first quarter, ALROSA fixed the current level of the cost of rough diamonds being sold. The Company’s conservative pricing policy is conditioned by the necessity of maintaining a moderate demand on the diamond market formed by April 2013," the company said in a statement.

During the first quarter of 2013, Alrosa made capital investments of RUB4bn ($127.8m), with about RUB1.8bn ($57.5m) in the construction of the underground mines Mir, Aikhal, and Udachny.

Alrosa’s mines produce 25% of the global diamond output.