Spot prices for October-loading Iraqi Basra Light crude in Asia have slipped to discounts against its official selling price and could stay weak for another month after the producer did not cut prices for November, four trade sources said on Tuesday.

Iraq kept the November official selling price for Basra Light to Asia unchanged even as Saudi Arabia trimmed its Arab Medium official price.

The November official prices put Basra Light at a 40 cents a barrel premium to Saudi Arabia’s Arab Medium, making the Iraqi oil the most expensive medium-sour grade produced in the Middle East.

Spot price discounts for Basra mean buyers with term contracts looking to re-sell their cargoes may be unwilling to let go of them as they will incur losses. That could curb trade volume and profits in one of the most popular grades in Asia.

October-loading cargoes of Basra Light destined for Asia have sold at discounts of more than 10 cents a barrel to its official price, the weakest level in months, trade sources said.

“This month it will be tough too,” a Singapore-based trader said, referring to sales of November-loading cargoes.

Iraq used to set monthly prices in line with Saudi Arabia, but the price gap widened after Iraq’s Oil Marketing Company (SOMO) saw robust demand for its oil, which has become a staple for refiners in India, China and South Korea.

The higher prices also reflect strong premiums fetched for Basra crude at auctions on the Dubai Mercantile Exchange (DME), the traders said. They declined to be named as they are not authorized to speak to the media.

“The problem is Iraq puts too much trust in DME auction levels,” said a trader who deals with Basra crude in Asia.

“They are not representative of the whole market because only traders who have short positions buy during the auction.”

Traders with short positions need to buy cargoes to fulfill a sales contract or to put them into refineries.

Iraq’s Oil Marketing Company now sells 2 million barrels each of Basra Light and Basra Heavy every month. It started auctioning its crude on the DME in April.

Exports of Basra crude from Iraq’s southern fields rose to an average 3.24 million barrels per day in September.