The rouble slumped to an over seven-month low against the dollar on Tuesday, extending hefty losses from the previous session, as fears over the possible impact of sanctions on oil and gas hampered the Russian currency.

At 0742 GMT, the rouble was 2.2% weaker against the dollar at 69.19, its weakest mark since May 11.

It had lost 2% to trade at 73.54 versus the euro , its weakest since May 6, and shed 2.4% against the yuan to 9.89, clipping a near six-month low.

A near 5% slump against the dollar on Monday was its largest drop in one session since July 5. The rouble remains the world's best-performing currency this year, supported by capital controls and an initial collapse in imports as a result of Western sanctions over Russia's war in Ukraine.

The rouble's weakening looks logical after the pressure of sanctions in recent weeks, said Veles Capital in a note, referencing the $60-per-dollar oil price cap and a ninth package of European Union sanctions against Moscow.

"On Monday, the pressure was seriously strengthened with information about preparations to introduce a 'ceiling' on the price of Russian gas from the start of 2023," Veles Capital said.

The rouble may recoup some losses later in the month, when exporters convert foreign currency revenues into roubles to pay local liabilities.

Brent crude oil, a global benchmark for Russia's main export, was down 0.1% at $79.7 a barrel.

Russian stock indexes opened at around two-month lows.

The dollar-denominated RTS index was down 3.4% at 957.4 points. The rouble-based MOEX Russian index was 1.2% lower at 2,103.7 points.

Shares in Lukoil slumped around 12.3% after the oil major's dividend record date.

For Russian equities guide see

For Russian treasury bonds see (Reporting by Alexander Marrow; Editing by Dhanya Ann Thoppil)