Russian Urals crude price differentials weakened in the Mediterranean and the Baltic due to ample supplies, traders said on Thursday. In the Platts window, Litasco sold to Shell a 80,000 tonne cargo in the Mediterranean loading on Jan. 18-22 at a discount of $1.45 a barrel to dated Brent, some 30-35 cents a barrel weaker than previous levels, traders said. Vitol unsuccessfully offered its Jan. 19-23 cargo at a discount of $1.45 a barrel, market participants said. Ample supplies of Urals in January were putting levels under pressure and some traders said they expected some cargoes to remain unsold after the New Year holidays. In the Platts window, Vitol offered in the Baltic a 100,000 tonne cargo for loading on Jan. 14-18 at a discount of $3.05 a barrel to dated Brent, traders said, but found no buyers. The asking price was some 25 cents weaker than previous estimates. Loadings from the Black Sea port of Novorossiisk were halted on Dec. 30 and 31 due to bad weather and traders said one or two cargoes from the December programme could be postponed until January. Turkey's Tupras on Dec. 30 closed a tender to buy 80,000-140,000 tonnes of Urals or 85,000 tonnes of CPC Blend for delivery on Jan. 20-30, but the results were still unknown.