Saudi Arabia, the world's biggest oil exporter, may invest up to $3.5 billion to build a plant in South Korea to process more profitable clean fuels, Seoul's energy ministry said.

State-owned Saudi Aramco has a 35 per cent stake in S-Oil Corp, but the energy ministry statement did not say whether Saudi Arabia would make the investment jointly with South Korea's third-biggest oil refiner.  S-Oil spokesman P G Kim said they had not been informed of the possible new investment.
Saudi Crown Prince Sultan bin Abdul-Aziz said during a recent meeting with visiting South Korean Prime Minister Lee Hae-chan he would order a positive consideration of the plan to build the Bunker-C cracking plant, the ministry said.
It said the investment could reach between $3.0 billion and $3.5 billion for the plant, which processes fuel oil, or Bunker-C oil, into more profitable gasoline, diesel and kerosene.
Asian refiners are pouring billions of dollars into upgrading their refineries in an effort to meet tightening fuel standards throughout the region.
By the end of 2007, countries that consume more than half of Asia's 24 million barrels per day (bpd) oil demand will move to lower-sulphur emission standards, a Reuters survey has found.