MOSCOW, July 31 (Reuters) - Urals crude oil differentials firmed in northwest Europe on high demand for August cargoes of the grade, while light Caspian CPC Blend differentials also improved as lower supply and arbitrage shipments lent support.
* Urals crude oil premiums to dated Brent moved closer to record highs in northwest Europe. High demand for the grade among European refiners was reflected in a rare appearance by Sweden's Preem, which usually buys in the physical market, in the Platts window during the session.
* Greece's Hellenic Petroleum recently purchased an August cargo of CPC Blend in a tender at dated Brent minus $1.50 per barrel, traders said. The deal level was some 50 cents per barrel firmer than recent estimates. Tengizchevroil was the seller, they added.
* Quite a few CPC Blend cargoes loading in August have been fixed for journeys to northwest Europe, Asia or the United States, traders said, which limits availability of the grade in Mediterranean.
* In the Platts window Preem bid for 100,000 tonnes of Urals loading from Baltic ports on Aug. 17-21 at dated Brent plus $0.75 per barrel, some 50 cents per barrel firmer than the recent estimates, but failed to find a seller.
* Trading firm Litasco bid for two Urals cargoes of 80,000 tonnes each loading from Novorossiisk on Aug. 11-15 and 13-17 at dated Brent plus $1.10 per barrel for each, in line with its bids on Tuesday. It again failed to find a seller.
* There were no bids or offers in the Platts window for CPC Blend or Azeri BTC, traders said.
* Libya's Sharara oilfield, the country's largest, was forced to shut down after a valve in the pipeline linking it to the Zawiya oil terminal was closed late Tuesday evening, state-owned National Oil Corp (NOC) said on Wednesday.
* Oil prices rose for a fifth day on Wednesday, supported by a larger-than-expected drop in U.S. inventories and investor expectations that the U.S. Federal Reserve will lower borrowing costs for the first time in more than a decade. (Reporting by Olga Yagova; Editing by Jan Harvey)