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MOSCOW, Oct 3 (Reuters) - Russia’s Rosneft has set the euro as the default currency for all its new export contracts including for crude oil, oil products, petrochemicals and liquefied petroleum gas, tender documents showed.

The switch from U.S. dollars, which happened in September according to the tender documents published on Rosneft’s website, is set to reduce the state-controlled firm’s vulnerability to potential fresh U.S. sanctions.

Washington has threatened to impose sanctions on Rosneft over its operations in Venezuela, a move which Rosneft says would be illegal.

Rosneft did not immediately reply to a Reuters request for comment. Rosneft is Russia’s top oil exporter, shipping abroad about 120 million tonnes of oil a year, or 2.4 million barrels per day.

“Rosneft has recently adjusted all the new contracts for export supplies to euros. We’ve been notified,” a trader at a company regularly buying from Rosneft told Reuters.

Reuters previously reported that Rosneft has turned to euros in its oil products sales.

According to three traders, Rosneft has named the euro as the default currency in all new contracts for its export sales starting from September.

As benchmark oil prices are quoted in dollars, Rosneft asks buyers to use the euro/dollar exchange rate published by Bloomberg one day prior to the set payment day, according to tender documents.

“Rosneft used to have the euro as one of the options, but since last month it’s the main option. We’ve been notified, but still it’s a visible change,” one of the traders said.

On Wednesday Rosneft issued a spot tender to sell 100,000 tonnes of Urals loading from Primorsk port on Oct. 27-28. “The default currency should be the euro,” the tender document published on the company’s website said.

In August, Rosneft closed a jumbo tender to sell Urals and CPC Blend crude oil for loading between October 2019 and March 2020 asking for bids in U.S. dollars. (Reporting by Olga Yagova; additional reporting by Natalia Chumakova in Moscow and Florence Tan in Singapore; editing by Katya Golubkova/Jason Neely/Susan Fenton)