Alrosa, De Beers’ Russian rival, is considering a stock market flotation in 2012 in a move that would open the traditionally closed diamond industry to outside investors.

Alrosa, controlled by Russia’s federal and regional governments, has long been the second-largest producer of diamonds behind De Beers. In 2009 the two companies mined half of the world’s diamonds, measured by carat volume. Both are private, limiting opportunities for investors in a commodity that is expected to face a supply crunch in coming years.

Fyodor Andreev, Alrosa’s chief executive, has said this would change next year. The Siberia-based miner is converting itself from a closed to an open joint stock company – or from a ZAO to an OAO in Russian corporate terminology. This will allow outside investors to buy new shares and relax ownership restrictions on the tightly-held miner.