This represented a gain of 57-per cent from the end of 1998 and an 83-per cent rise from the 12-year low of $10.35 hit in December last year.

New York traders said NYMEX had lost only modest ground in Asia on Tuesday, indicating that the market could be building to try to test $19.00 again in New York later on Tuesday.

The firmer tone of NYMEX should bolster Brent crude prices on the International Petroleum Exchange (IPE) in London later on Tuesday. The market was closed on Monday due to a British holiday. Prices are largely being supported by optimism that the often-fractious OPEC cartel is maintaining production discipline andkeeping a tight rein on oil supplies.

How well founded this optimism is should emerge this week or early next week when secondary market sources publish estimates of April production. A preliminary survey last week showed that OPEC, which has made various pledges in the past year to cut a total 15.8 per cent from its 27.289 million bpd output, was 81-per cent compliant with its promises. Iraq is excluded from the agreement.

Matt Sims, a broker with ED&F Man in New York, said OPEC discipline could be maintained so long as oil prices continued to rise. But once prices have fully factored in OPEC's cuts and they stabilise, it might encourage some producers to start cheating on their quotas.

"At a certain point, everything will be built into the price. Then we will start to look out for cheating," he said. Strongly rising oil prices in the past has been a cue for cheating among the OPEC members, but last week a Gulf source, familiar with Saudi thinking, said the kingdom and OPEC king-pin expected 100-percent compliance with the cuts in May.

On Monday United Arab Emirates (UAE) oil Minister Obaid bin Saif al-Nasseri said he was satisfied with the rise in oil prices. "We hope this will be sustained and improve in the future,"he told reporters in Abu Dhabi.

Abu Dhabi announced at the weekend a 21-22 per cent increase in government selling prices for its crude in April compared with March levels. Oman and Qatar have followed suit with similar price increases for their April sales. The prices are set retroactively.

Saudi Arabia, which exports some six million barrels per day, is expected to announce its prices in coming days. But Kuwait Oil Minister Sheikh Saud Nasser al-Sabah created some confusion with comments over the weekend that Kuwait was planning to cut no more than 7.25 per cent -- sufficient to meet its OPEC pledge.

Late last week traders globally had received notices from Kuwait saying the Emirate planned to cut 7.25 per cent, plus an additional 4.56 per centage points, in May. The OilMinister's comments immediately put into doubt the depth of Kuwait's supply cuts. "Our total cuts are not 11 per cent. I don't know where they got this from. The total amount is 7.25 per cent," he said on Saturday.