SINGAPORE, Nov 1 (Reuters) - The Middle East crude market strengthened on Thursday as DME Oman's premium over Dubai quotes jumped on aggressive bidding by Shell, traders said. Front-month Oman contracts were quoted at a premium of $2.56 a barrel over Dubai quotes, compared with a 57-cents per barrel discount on Wednesday. *TRADES - Shell bought three January Dubai partials from Philbro, paying $106.85 per barrel for two partials and $106.80 per barrel for the third. - Shell also bought one January Dubai partial from Gunvor at $106.85 per barrel. - Philbro also sold two January Dubai partials to Trafigura at $106.85 per barrel. *TENDERS: - Formosa is seeking 2 million barrels of January Basra Light via a tender that closes on Friday. *OSP: - Dubai crude oil quoted by price-reporting agency Platts averaged $108.87 a barrel for October, down $2.35 from September, traders said on Thursday. The average is used as the basis for the Abu Dhabi and Qatari retroactive October official selling prices (OSPs), which are set as differentials to Dubai. - The official selling price (OSP) for Oman crude in December will drop by $2.57 to $108.67 a barrel, Reuters calculations based on data from the Dubai Mercantile Exchange (DME) showed on Thursday. The December Oman OSP is the average of the daily Oman settlements at 0830 GMT in October for the front-month contract OQc1. The Dubai crude OSP, set at parity to DME Oman, was also calculated at $108.67 a barrel. *ALLOCATIONS: - Abu Dhabi National Oil Co (ADNOC), the main exporter for OPEC member the United Arab Emirates, and Qatar will supply full contractual crude oil volumes to Asia in December, steady from November, industry sources said on Thursday. ADNOC has notified Asian buyers it will supply its four main grades - Murban, Lower Zakum, Umm Shaif and Upper Zakum - at contractual volumes in December, while Qatar will do the same for its Marine and Land grades, the sources said. While ADNOC has not yet said whether it would give buyers the option of asking for all grades' cargoes to be 5 percent more or less than contracted volumes for December loading, buyers of Qatari crude will have the option, they added. ADNOC did not grant the so-called "plus tolerance" option to Murban crude for November loading, capping the maximum volumes that the buyers can take to the contractual volumes, sources said. But it afforded the normal tolerance for other three grades. *MARKET NEWS - OPEC oil output has risen slightly in October as extra supplies from Iraq, Angola and Libya have offset disruptions in Nigeria and a further decline in Iran to its lowest in two decades, a Reuters survey found on Wednesday. - South Korea's crude oil imports in October fell 2.2 percent from a year earlier to 81 million barrels, preliminary customs data released by the economy ministry showed on Thursday. - Canada is likely to extend its review of the $15.1 billion bid by China's CNOOC Ltd for oil producer Nexen Inc beyond next week's deadline to allow more time for the government to formulate a broad framework on foreign investment, two sources close to the matter said on Wednesday. CRUDE Price Prev Change JAN DME Oman diff to Dubai 2.56 1.58 +0.98 DEC Brent 108.64 109.57 -0.93 JAN Dubai 104.39 105.12 -0.73 JAN DME Oman 106.95 106.70 -0.25 DEC Brent/Dubai EFS DUB-EFS-1M 3.50 3.75 -0.25 PRODUCT CRACKS DEC fuel oil crack -9.41 -9.17 -0.24 DEC gasoil crack 18.98 18.83 +0.15 DEC naphtha crack -5.86 -6.63 +0.76 COMPLEX REFINERY MARGINS Today 5.76 Last 5 days 6.73 Last 365 days 7.31

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