"There were some buyer enquiries for long range (LR) vessel-sized cargoes but we are not quoting any numbers," a source at SK Corp said.

Traders also said that for the September market, South Korean refiners regular practise of price slashing abated, despite the prolonged absence of China import demand.

This contrasted with May when South Korean refineries offered cargoes at heavy discounts to Singapore benchmark prices to battle against a slump in the market. The price cuts forced open an arbitrage for exports to the faraway Latin America market. Last week, the arbitrage opened again as Singapore prices dipped to 12-year lows.

No cargoes were fixed this time although at least one vessel was put on reserve by a Western trader, shipping sources said.

In South Korea, only SK Corp and LG-Caltex canoffer LR sized cargoes of 80,000 deadweight tonnes, which could save freight economics for traders making the 30-45 days voyage to Latin America.

But for September and October, SK Corp plans to run its 865,000 barrel-per-day (bpd) refinery at 650,000-bpd and 700,000-bpd respectively.

Prices were expected to firm marginally in October from the discounts of 50-60 cents below Singapore prices offered in September, traders said.

"If the market gets really tight, we can supply a little but not LR size," the SK Corp source said.

A source at the export-oriented 35-per cent Saudi Aramco owned Ssangyong Oil refinery said it was asking buyers to defer a couple of cargoes sold earlier on the spot market.

"We are now checking our buyer's positions to adjust our lifting schedule. It's related to our crude run cuts," the source said.

A Ssangyong source said on Monday that they were running their 500,000 to 525,000 barrel-per-day (bpd) refinery at 10-per cent lower in September with a 65,000-bpd gasoil-producinghydrocracker slashing runs to 70-per cent.

Buyers of Ssangyong diesel cargo, including a European trader said the delays posed no problem, but came as a surprise.

"Maybe our buyers will agree to our request," the Ssangyong source said. "The market is not too good."

The signs of Korean refineries adopting a less aggressive stance came to the fore in the Petron Corp tender to buy September diesel, traders said.

Many Korean refiners did not even participate in a prompt Petron tender. The proximity of the two countries means that South Korea offers the cheapest source, they said.

The tender, issued by Petron last week, sought a 150,000-200,000 barrel cargo of 0.5-per cent sulphur diesel for delivery September 23-24 into Limay.

"We were invited but we had no availabilities in September," a source at Hyundai Oil said. "As you may know, we started our turnaround."

Hyundai starts a turnaround of a 240,000-bpd CDU for one month maintenance for one-month in September and will run only at110,000-bpd.