SINGAPORE - Qatar Energy raised the price for term cargoes of al-Shaheen crude oil loading in October to a four-month high, trade sources said on Friday, as demand for Middle Eastern oil increased after Saudi Arabia prolonged its voluntary supply cut.

The October price was set at $2.10 a barrel above Dubai quotes, up 42 cents from September's $1.68 a barrel and reaching the highest since June.

Spot premiums for Middle Eastern sour crude stayed firm this month, supported by supply tightness concerns as top oil exporter Saudi Arabia extended its 1 million barrels per day unilateral output cut to September, even as the sluggish Chinese economic data pressured down global oil benchmarks Brent and WTI.

The term price was decided after Qatar Energy sold three al-Shaheen crude cargoes for October-loading via its monthly tender.

The total number of al-Shaheen crude available for trade for October is the same as September at 16 cargoes, although Qatar Energy offered two cargoes less in the tender compared with the prior month.

Shell, Unipec and Vitol likely bought the three cargoes via the tender at price range of $1.90 to $2.11 a barrel above Dubai quotes.

The cargoes are to load on Oct. 1-2, 14-15 and 29-30.

(Reporting by Muyu Xu; Editing by Christian Schmollinger and Sherry Jacob-Phillips)