Cash Dubai came under pressure after six March partials were sold by Shell and Unipec to Vitol and Hetco at $51.40-$51.50 a barrel, nearly $3 lower than Friday. Cash Dubai's discount to Dubai swap widened close to $1 to $2.70 a barrel.
Mercuria sold a May partial to Shell at $54.30 a barrel, which puts the March-May spread at a wide $2.90 a barrel.
Weakness in Dubai stretched its prompt spread with Brent to the widest since mid-December. Brent-Dubai Exchange of Futures for Swaps (EFS), or Brent's premium to Dubai swaps, widened 45 cents to $2.30 a barrel for February and was at $2.19 for March.
Traders are awaiting official selling prices (OSPs) from Gulf producers to gauge differentials for March-loading crude trading this month.
Saudi Aramco is likely to raise the February OSPs for Arab Light and Medium to Asia by 20-30 cents due to a narrower contango for Dubai monthly spreads, traders said. The Arab Heavy OSP could rise by 60 cents a barrel, they said. But the world's top exporter could temper price hikes to stay competitive.
ADNOC and Qatar are expected to raise the December OSP differentials to Dubai quotes for Murban and Marine crude by about 30 cents a barrel while that for Das may post a higher increase after February-loading cargoes were sold at relatively higher premiums.
DME OMAN
DME Oman for March settled at $52.04, down $1.97, at 0830 GMT. This puts DME Oman at $2.06 a barrel below Dubai swaps, against a discount of $1.86 in the previous session.
MARKET NEWS
Russia's 2014 oil output hit a post-Soviet record high average of 10.58 million barrels per day (bpd), rising by 0.7 percent helped by small non-state producers, Energy Ministry data showed.
Forces loyal to Libya's internationally recognised government on Saturday staged air strikes on the commercial port of Misrata, a western city allied to a group that holds the capital Tripoli, both sides said.
Indonesian state-owned energy firm Pertamina will take over the purchase of crude and oil products from its trading arm Petral this month following recommendations from a government panel, two sources with direct knowledge of the matter said.