Moscow has yet to approve an increase in oil supplies to neighbour Belarus, despite pledges to do so, amid a row over gas prices, industry sources told Reuters on Wednesday.
Traders said some oil producers may add cargoes to loading plans elsewhere due to uncertainty over shipments to Belarus.
Russia's oil output set a new post-Soviet era record high in October, rising 0.1 percent from September to 11.2 million barrels per day (bpd), energy ministry data showed on Wednesday.
The rise underscores the difficulty the government could have in freezing output levels as part of a global pact with other top producers in order to support oil prices.
In northwest Europe, BP bid for 100,000 tonnes of Urals on Nov. 12-16 up to dated Brent minus $2.00 a barrel without finding a seller, traders said. That was up by 30 cents a barrel from Shell's bid on Tuesday, but slightly below the latest estimates for the grade in northwest Europe.
In the Mediterranean, Litasco offered 140,000 tonnes of Urals ex-Novorossiisk on Nov. 23-27 down to dated Brent minus $1.80 a barrel before withdrawing.
In lighter grades, Vitol bid for 85,000 tonnes of CPC Blend on Nov. 16-20 up to dated Brent minus $0.65 a barrel but withdrew.
The CPC Blend oil loading plan for November was slightly revised on Wednesday, to a monthly record-high of 4.44 million tonnes from 4.42 million tonnes in a preliminary plan, the loading schedule obtained by Reuters showed.
This is up by 440,000 tonnes from the October plan.
There was no activity in Azeri Light and Siberian Light in the Platts window, traders said.