MOSCOW: The Russian rouble eased on Wednesday despite a surprise decrease in state purchases of foreign currency, while the stocks lacked momentum ahead of U.S. holiday.

Russia's Finance Ministry said it was reducing total purchases between July 6 and Aug 6 to the equivalent of 347.7 billion roubles ($5.50 billion) because revenues from oil and gas exports were lower than expected.

Analysts polled by Reuters had predicted the ministry would increase purchases of foreign currency and buy a total of 395.0 billion roubles.

At 1246 GMT the rouble was 0.25 percent weaker against the dollar at 63.31 and shed 0.15 percent to trade at 73.72 versus the euro.

"The finance ministry's purchases will continue to put downward pressure on the rouble given the seasonally weak current account and the global withdrawal to the dollar assets," Raiffeisen analysts said.

Analysts at FocusEconomics expect the rouble to strengthen by the year-end, but it is still down notably from the beginning of 2018 hit by the new U.S. sanctions imposed on some Russian businessmen and their assets.

"Our panel sees the rouble strengthening by the end of the year, ending 2018 at 60.9 per dollar and 2019 at 61.7," analysts said.

Brent crude oil, a global benchmark for Russia's main export, was up 0.31 percent at $78.00 a barrel.

Russian stock indexes lacked momentum, stabilising at levels of previous days. U.S. markets will be closed for the Independence Day holiday on Wednesday.

The dollar-denominated RTS index was 0.12 percent higher at 1,148.83, while its rouble-based peer MOEX was 0.28  percent higher at 2,308.10 points.