A London-based trading arm of a Japanese trading company -- which earlier reportedly sold one million barrels of Brent to a US major in Asia -- was rumoured to have also sold about four million barrels of the crude to Singapore and China.

The cargoes are believed to be due to arrive between February 15 to March 15, they said.

The buyers are believed to be European and US majors, as well as a Chinese trading unit. The crude was rumoured to have been sold at a premium of about $1.00 per barrel over Dubai quotes on a cost and freight basis. The transactions were seen as representing the latest sign of Asia's appetite for Western sweet grades.

Although Japanese refiners maintained a low profile, key Middle East crude grades continued to trade at firm levels.

Malaysia is thought to have purchased three to four March Omancargoes at MOG plus 19 cents from a French major, a US major and a Finnish energy company in a closed tender.

Elsewhere, the French major is believed to have sold 500,000 barrels of March Qatar Land to a Japanese refiner in exchange for a March Murban. The swap was rumoured done at a premium of 18 cents above the official selling price for both crudes.

A Japanese trader was believed to have sold a March Qatar Land at QGPC plus 18 cents to a US major.

A March Murban cargo was most recently believed to have been sold by a European major to a Japanese refiner at ADNOC plus 23 cents. The premium is believed to be the highest so far for March Murban.

At least one major with a March Murban cargo has backed off from the market in expectation that premiums for the key Middle East crude would rise further due to dwindling availability.

A Japanese trader said it had sold its March Qatar Marine cargo at a higher premium than that of the last deal done at QGPC plus 15 cents.

Lower Zakum and Umm Shaif arebelieved to have all been committed for March. Only a handful of Oman cargoes are believed available for March.

Yemen has asked buyers to submit their bids for Masila crude for lifting in March by Friday. The bids will be considered by Yemen in setting its official selling price.

Traders in Singapore were away to mark a National holiday for Eid al-Fitr.