SAUDI Arabia will probably deepen discounts for crude supplies to Asia after leading Organisation of Petroleum Exporting Countries (Opec) to maintain the group's output target amid a global battle for market share.

The world's biggest oil exporter will announce January official selling prices to buyers in Asia this week after lifting its Arab Light grade from the lowest level in almost six years a month earlier.

The largest producer in the Opec may offer bigger discounts, according to 12 of 13 respondents in a Bloomberg News survey of traders. One participant forecast differentials to be unchanged.

Saudi Arabia is discounting its crude as Opec's decision to maintain production quotas prompts speculation the group is prepared to let prices fall to defend its market share against more expensive United States shale output.

Benchmark futures contracts have collapsed almost 40 per cent from a June peak as competition between suppliers increased amid slowing demand.

"There's no question that the Saudis want to maintain market share," Victor Shum, a Singapore-based vice-president at IHS Inc, an industry consultant, said by phone on Wednesday.

"They could cut prices to make them competitive in an environment that still seems to be under a lot of downward pressure."

Arab Light, the largest Saudi oil stream, will sell in Asia next month at US$2 (RM6.90) a barrel below the average of Oman and Dubai grades, Masahi Nakayama, general manager of the crude and tanker department at Cosmo Oil Co, a Japanese refiner, said last week.

Saudi Arabian Oil Co is offering the grade at 10 cents a barrel below Oman and Dubai this month, according to November 3 statement from the company known as Saudi Aramco. That's up from a discount of US$1.05 for November, the widest since December 2008.

"If the discount for Arabian Light crude surpasses US$1, it will be quite unusual for January when oil demand for heating peaks in the Northern Hemisphere," said Setoh Shohei, a Tokyo-based manager at Japan Biofuels Supply LLP, a joint venture of the nation's refiners, and a former crude trader. Bloomberg