LONDON- Russia's rouble tumbled to a fresh record low in thin offshore trade on Monday, with local markets closed for trading until at least Wednesday.

The rouble weakened to 133.5 to the dollar after closing at 121.037 on Friday, according to Refinitiv data. On the EBS trading platform, the rouble weakened as far as 141.00 to the dollar.

Bid/offer spreads were between 10 and 15 cents, pointing to an increasingly illiquid market.

Trading on the MOEX Moscow exchange is scheduled to be closed until Wednesday for a bank holiday.

The rouble has lost more than 40% of its value against the greenback since the start of the year, with losses sharply accelerating since Russia invaded Ukraine on Feb. 24, which sparking sweeping sanctions from Western capitals.

The curbs on Russia, its lenders, corporates and key individuals, as well as counter measures from Moscow, have cut Russian assets increasingly out of global financial markets and have made it tricky for investors to trade any securities.

"It has become very difficult to trade the rouble after the sanctions," said Aaron Hurd, senior portfolio manager, currency, at State Street Global Advisors. "Liquidity has vanished and markets have become very volatile."

Russia calls its actions in Ukraine a "special operation."

Stocks last traded on Feb. 25 on Moscow's bourse.

Five-year credit default swaps in Russia - reflecting the cost to insure exposure to the country's sovereign debt - soared to a record 2,619 basis points compared to 1,725 basis points on Friday, data from IHS Markit showed.

Trades on Russia's sovereign dollar- and euro-denominated debt have all but ground to a halt, with some issues bid at around 20 cents in the dollar or euro .

"With Russian prices on the euro bond somewhere around 20, this is going to go on for a long, long time, and nobody wants to be associated with (the rouble)," said Gabriel Sterne, head of global EM research at Oxford Economics.

"Just sell it and take a loss. You have to interpret the price movements as: there's almost infinite supply and very little demand for these assets at the moment. It's now just a matter of an orderly disposal of Russian assets."

Rouble implied volatility gauges - a measure of demand for options on the currency rising or falling against the dollar - have stayed near record highs hit last week, with the one-week gauge above 84% and the one month one above 94%.

The rouble's collapse has also hit trading volumes. Turnover on the Russian currency on EBS fell more than 80% on Friday compared to the end of February.

(Reporting by Karin Strohecker; Additional reporting by Saikat Chatterjee and Anisha Sircar; Editing by Edmund Blair and Mark Potter)