(Updates with exchange-rate effect in third paragraph.)

Oct. 20 (Bloomberg) -- Russia’s international currency and gold reserves jumped $7.3 billion last week, the most since April 2010, after the euro strengthened against the dollar.

The stockpile, the world’s third largest, reached $517.7 billion on Oct. 14, the first advance in six weeks, the Moscow- based bank said in a statement today.

The increase was mostly caused by a strengthening euro, which accounts for more than 40 percent of reserves, Vladimir Tikhomirov, chief economist at Moscow-based Otkritie Capital, said today in an e-mailed research note. Excluding revaluations, reserves probably fell by $800 million, he said.

The revaluation of euro-denominated assets accounted for $6.4 billion of last week’s gain, according to Tikhomirov. The euro surged 3.8 percent against the dollar to 1.3882 from 1.3378 last week.

--Editors: Balazs Penz, Jeffrey Donovan

To contact the reporter on this story: Scott Rose in Moscow at rrose10@bloomberg.net

To contact the editor responsible for this story: Balazs Penz at bpenz@bloomberg.net