But measures are being considered in Tokyo, on a more limited scale than Europe's Sulphur Emission Control Areas (SECA), which will require cleaner fuel from mid-2006.

"There will be more SECAs in the future. That's a reality. We won't argue with the lower-sulphur limits because at the end of the day, you and I will be breathing the air," Ian Adams, secretary-general of the International Bunker Industry Association (IBIA), told a Shanghai bunkering conference.

The European Union will impose a 1.5 percent sulphur limit for fuels used by all ships in the Baltic Sea from next May, extending to ships in the North Sea and English Channel in 2007.

Experts say the change will force Russia, a major exporter of high-sulphur marine fuels, to reroute exports to the Mediterranean, Asia and the United States, where most fuel still has a sulphur content of around 3.5 percent.

"I don't think this is going to happen elsewhere in the world," said Robert Chandran, president and chief executive officer of leading US bunker supplier Chemoil-ITC, which says it sells about 5 percent of shipping fuel globally.

"Most of the global fleet already burns fuel oil with 2.6-2.7 percent sulphur anyway, and most of the crudes in the world, other than the Saudi ones, are not high in sulphur. I think this low-sulphur issue will remain an experiment in Northwest Europe."

However, the Tokyo Metropolitan Government said separately on Tuesday it was considering tightening limits in Tokyo Bay, first through a voluntary request to tanker owners.

NO RUSH

Major port operators in Asia say they are in no rush to implement new standards that could threaten their large bunker industries and drive up shipping costs.

"We have no plans to reduce the sulphur content in bunker fuel beyond the current requirements," said S.Y. Tsui, Director of Marine for Hong Kong, the world's biggest container port.

An industry official in Singapore, which supplies nearly half of Asia's total marine fuels, said: "The action in Europe is a unilateral action by their governments that has no impact on us.

"We always have and always will follow international standards as set by the IMO and there are no signs that they are going to (impose new limits)."

Asia also lags Europe in clean motor fuel rules, although big consumers such as India and China have raised standards this year, while South Korea and Australia will do so in 2006.

The European regulation came after the EU parliament identified ships as the single-biggest source of sulphur dioxide (SO2) in Europe because the maritime sector had lagged land-based industry in environmental improvement.

LIMITED ASIA IMPACT

The new European limits will have minimal impact on Asia's bunker market, since ships must only burn cleaner fuel on two to three days of a 30-day voyage to Europe. Only about 10-20 percent of tankers refuelling in Asia sail for Europe.

"The vessels only need to segregate the low-sulphur bunkers in separate tanks and activate them only when they enter a SECA zone," said a bunker buyer with an international shipping firm.

"We would stock up sufficient supplies of low-sulphur bunkers in Europe for use when the ship leaves and return to port."

Owners will be discouraged from taking on lower-sulphur fuels while stopping in Asia by the sheer lack of supplies.

In Asia, only South Korean refiner SK Corp. produces enough low-sulphur fuel oil for export, mostly to Japan as burning fuel for utilities. SK exports an average of 100,000 tonnes each month, or about 5 percent of Singapore's sales.