MOSCOW â€" Shares of the Russian diamond-mining company Alrosa closed slightly higher on Thursday in their first day of trading, indicating some investor enthusiasm for a stock that offers a way to place a market bet on the price of diamonds.
Alrosa, which owns licenses to the world’s largest-known reserves of unmined diamonds, had set the price of the new shares via a secondary stock offering at 35 rubles a share, or about $1.09, on Monday. The new shares were available for trading for the first time for one hour during the end of the trading day Thursday on the Micex stock exchange. They closed about 3 percent above their offer price, at 36.22 rubles, or $1.13.
‘‘Nobody rushed to trade in the new shares after the settlement,’’ explained one financial industry adviser who helped with the placement but was not authorized to discuss it publicly.
The issue raised a total of $1.3 billion. Although it is not Alrosa’s first offering, it garnered greater interest than the 2011 initial public offering, which released only a small number of shares that traded thinly.
As such, it was a qualified success for a company that is testing investors’ interest in the market for unfinished diamonds.
De Beers, Alrosa’s main competitor, is a majority-owned subsidiary of a large, diversified mining company, Anglo American, so doesn’t trade separately on a public exchange.
Demand for diamonds is expected to rise as Chinese people become wealthier and buy more diamond engagement rings and other jewelry.
On the flip side, the industry’s future has been clouded since 2008 when European Union anti-monopoly regulators forced the Russians and De Beers to unwind a cartel that had propped up prices for decades.
The two companies dominate the diamond business. Alrosa produces more carats of diamonds annually than De Beers, but De Beers has higher revenue, earning more from each stone as its mines yield a higher grade of gem.
A carat is a measure of weight but not quality. Although per-carat prices vary greatly, overall diamond prices have more than doubled since 2009.
In the share placement, the Russian federal government, a regional government and the company spun off equity representing a 16 percent stake in the company.
