Singapore, July 04 (QNA) - Top oil exporter Saudi Arabia will cut or keep steady the official selling prices (OSPs) of most of its crudes to Asia for August as refining margins come under pressure, refiners and traders polled said on Friday. The eight refiners and traders polled expected Arab Heavy''s discount to Oman/Dubai to be widened, and none forecast Arab Light or Extra Light''s premiums to rise further, the "Gulfnews" reported. "With the current levels, we cannot find good economics for heavy grades," a trader with a refiner said. Saudi crude OSPs are usually released around the fifth of each month, and set the trend for Iranian, Kuwaiti and Iraqi prices, affecting some 7 million barrels per day (bpd) of crude heading to Asia. According to the Gulfnews, refining margins in June turned negative in Asia for Dubai crude run in a simple refinery, leading to a 40-cent loss for refiners, Reuters data show, while margins at a complex refinery would have averaged a $3.00 profit. The benchmark Asian 180-centistoke (cst) fuel oil crack averaged $7.38 a barrel below Dubai swaps in June, down $2.91 from May on prospects of higher arbitrage flows in July. The weaker fuel oil crack over the month left little room for Saudi Arabia to raise the price of its heavy grades further, after it hiked them to their highest differentials since 2003 for July, traders said. Abu Dhabi National Oil Co (Adnoc) cut Murban''s premium to Dubai quotes by 6 cents a barrel to $2.24 in its latest retroactive June OSP, the first time since December that it did not raise the grade''s premium, which could prompt Saudi Aramco to also cut the price of Arab Extra Light. But flagship Arab Light crude stood a better chance to be left unchanged despite the weaker fuel oil crack and still low gas oil crack, a trader said, after rival Oman crude fetched strong premiums to Dubai quotes of up to 80 cents, stronger than May''s highest deal at a 65-cent premium. (QNA)