SINGAPORE, July 12 (Reuters) -Middle East crude benchmarks Oman, Dubai and Murban closed the trading week firmer, with one China oil major being the biggest buyer for the week against a backdrop of mixed market expectations for September, though east-west spreads neared a five-month high.

Buying interest in the open window was firm from key major Petrochina mostly through the week, with some traders saying the price action could be related to the forward months' trading market structure, though further details could not be confirmed.

The exchange of futures for swaps closed Friday's trading session at $2.28 a barrel, reflecting the strength in the West, according to some traders.

Markets ended up in mixed expectations with respect to demand-supply fundamentals, though prices and cash premiums rebounded mostly in the latter half of the week with support from the West being a key driver.

Some traders remained cautious on Friday because of the weakness in the performance of downstream gasoline and diesel margins, though overall complex refining margins were little changed week on week.

KUWAIT OSP

Meanwhile, Kuwait has cut the official selling price (OSP) for Kuwait Export Crude (KEC) to Asia in August by 70 cents from the previous month to $1.25 a barrel above the average of Oman/Dubai quotes, a price document reviewed by Reuters showed on Friday.

CHINA DATA

China's crude oil imports in June dropped 11% from a high base a year earlier and first-half imports fell 2.3% in a rare year-to-date decline, data showed on Friday, as fuel demand disappoints and as independent refiners reduced production due to weak profit margins.

SINGAPORE CASH DEALS

Cash Dubai's premium to swaps climbed 4 cents to $1.84 a barrel, almost a two-week high.

PRICES ($/BBL)

NEWS

- Japanese companies foreseeing a growing surplus in stocks of liquefied natural gas (LNG) as their demand for the fuel wanes in coming years, are scrambling to invest in regional markets to provide potential outlets to sell the gas.

- A Chevron-chartered oil tanker that was seized by Iran more than a year ago was heading for international waters on Thursday, LSEG ship tracking data showed.

For crude prices, oil product cracks and refining margins, please click on the RICs below.

Reporting by Trixie Yap and Florence Tan; Editing by Shreya Biswas

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