MOSCOW, March 28 (Reuters) -
* Urals differentials were unchanged in quiet trade on Tuesday, but some traders saw signs that prices for Russian grade may rise due to healthier refining margins and arbitrage opportunities to Asia.
* There were no bids or offers for Urals, CPC Blend or Siberian Light in the Platts window on Tuesday, traders said.
* Urals refining margins improved on Tuesday for complex refineries in Mediterranean to $5.06 a barrel to BFOE compared with $4.09 a barrel on average for the last five days, Reuters data shows.
* Opportunities for Urals arbitrage to Asia were still wide. Three Urals VLCCs loading in March were sent to Asia as well as at least four 140,000-tonne tankers loading from Novorossiisk, traders said and shipping reports show.
* Brent-Dubai spread remains thin, at $1.19 a barrel, which helps Urals arbitrage to Asia. DUB-EFS-1M
* Azeri Light remains under pressure along with other sweet grades in Mediterranean region due to an ample supply.
* In the Platts window SOCAR offered 85,000 tonnes of Azeri Light loading on April 17-21 at premium of $1.60 a barrel to BFOE, but failed to find a buyer and withdrew the offer, traders said.
* Russia will reduce Urals oil exports from the Baltic Sea port of Primorsk by around 12 percent to 44 million tonnes (884,000 barrels per day) this year due to using some of the pipeline capacity for shipments of diesel, oil pipeline monopoly Transneft said on Tuesday.
* Oil production at the western Libyan fields of Sharara and Wafa has been blocked by armed factions, reducing output by 252,000 barrels per day (bpd), a source at the National Oil Corporation (NOC) said on Tuesday.
* Russia's Zarubezhneft awarded a tender on Monday to sell 600,000 tonnes of Urals loading from Primorsk in April-June 2017 to Glencore, traders said.
* Rosneft awarded Trafigura 140,000 tonnes of Urals loading from Novorossiisk on April 14-15. Trafigura will load the cargo on April 20-21 as Rosneft exchanged the loading positions with Lukoil that will load its cargo on April 14-15 instead of Rosneft.
* PKN Orlen awarded Total a tender to buy 100,000 tonnes of Urals loading from Baltic ports on April 9-13 for delivery to Butinge, traders said. (Reporting by Olga Yagova)