Russia's central bank has started buying Canadian dollars and securities, First Deputy Chairman Alexei Ulyukayev said.

"The Canadian financial market isn't very big," Mr. Ulyukayev told reporters in the central Russian city of Tula Wednesday. The bank can invest a "significant amount" in the Canadian currency, "but the securities market is limited." He didn't specify how much the bank had invested.

Russia aims to diversify its reserves, the world's third-largest stockpile, and promote regional currencies in trade and finance to reduce risks posed by the dominance of the U.S. dollar. The central bank said in November that it planned to add Canada's dollar to its reserves and might consider including other currencies later.

Bank Rossii is "discussing" the possibility of buying Australian dollars, chairman Sergei Ignatiev said last month.

Russia's reserves were previously made up of 47% U.S. dollars, 41% euros, 10% pounds and 2% yen. The stockpile fell 2% in December to US$439-billion, the central bank said on Jan. 15. The country keeps about 35% of its international reserves in U.S. Treasury debt.

The central bank doesn't plan to shift reserves to private corporate assets from sovereign bonds, Mr. Ulyukayev said.

"We are such conservative investors that we won't invest in private bonds even though spreads are smaller," he said.