The Russian rouble weakened slightly against the U.S. dollar on Wednesday, ignoring the European Commission's proposal to impose new sanctions on Russia, including a lower cap on Russian oil prices.

The commission proposed an 18th package of sanctions against Russia on June 10 for its invasion of Ukraine, taking aim at Moscow's energy revenue, its banks and its military industry.

It has also proposed lowering the Group of Seven nations' (G7) price cap on Russian crude oil to $45 a barrel, from $60 a barrel, in a bid to cut Russia's energy revenue.

By 0945 GMT, the rouble was down 0.2% at 78.60 per U.S. dollar, according to LSEG data based on over-the-counter quotes. On June 10, the rouble strengthened by 0.7% against the dollar.

The rouble plummeted by up to 15% on U.S. sanctions against Gazprombank, which handled Russia's energy payments, imposed in November last year. The Russian currency has rallied by around 40% against the dollar so far this year.

"Negative for sentiment, but there is still little certainty," BCS brokerage analysts said in comments on the EU sanctions proposals.

"The history of introducing logistical restrictions since 2022 shows a temporary widening of price discounts on Russian hydrocarbons, followed by normalization without affecting production and export volumes. It is likely that this will happen again this time," they said.

Against the Chinese yuan, the most traded foreign currency in Russia, the rouble weakened by 0.9% to 10.90 on the Moscow Stock Exchange. The central bank uses yuan for foreign exchange interventions.

(Reporting by Gleb Bryanski; Editing by Rachna Uppal)