The Central Bank was forced to ease its trading band for the 12th time in three weeks Wednesday after the ruble strengthened against the dollar to the highest level in almost two months on climbing oil prices.

The ruble added 0.7 percent to 29.6050 per dollar in Moscow trading. It was 0.2 percent stronger at 40.3097 per euro, leaving the ruble at 34.4208, the strongest since Dec. 26, 2008, against the currency basket, which is used to manage swings that hurt Russian exporters.

“With the economy performing better than expected, oil hitting $80 and the Greek story fading out, the ruble’s move has been more aggressive than many have anticipated,” said Ivan Tchakarov, an economist at Nomura Holdings in London.

The Central Bank set a new trading band of 34.40 to 37.40, compared with 34.50 to 37.50 previously, allowing the ruble to appreciate twice in 5 kopek increments after buying between $1.7 billion and $2.3 billion to slow the currency’s gains, said Sergei Romanchuk, head of foreign currency and money markets at AKB Metallinvest Bank in Moscow. The Central Bank probably bought as much as $2 billion on Tuesday, according to ING.