Several hours earlier, Formosa Petrochemical, the only private oil refiner on the island, announced the same amount of price increase, also effective from 12:00 a.m. this morning.

After the hike, 92-octane unleaded gasoline will sell for NT$30 per liter, compared to the corresponding figure of NT$30.7 for 95-octane unleaded gasoline, NT$32.2 for 98-octane unleaded gasoline, and NT$30.7 for E3 ethanol-blended gasoline.

Meanwhile, the new price for both super diesel oil and biodiesel will be NT$27.5 per liter. Marine diesel oil will sell for NT$27,000 per kiloliter, compared to NT$20,293 for fishing boat fuel A.

Under a revised floating oil pricing system, the CPC will adjust its domestic sales prices on a monthly basis in accordance with the average international crude oil price registered during the preceding month, according to CPC officials.

The officials said that the oil price hike announced yesterday was mainly fueled by the fact that average Dubai and Brent crude oil prices hit a high of US$78.73 per barrel in September, higher than the US$74.41 posted in September.

On another front, in order to better take care of underprivileged groups and traditional industries, the government has decided not to raise the prices for fuel oil and tanked gas, despite the sharp hike in gasoline and diesel oil prices.

Also yesterday, Vice Premier Chiou I-jen said the Executive Yuan will continue to follow the floating oil pricing mechanism, which was put into practice in September to reflect the fluctuations in international crude oil prices.

Chiou noted that domestic oil prices have increased by 12 percent and will soon hit the ceiling of 15 percent. If the public is still feeling the pressure at that time, the government will consider lowering gas prices, he said.

He added that freezing gas prices will not solve the problem at its source, and there is no reason to freeze gasoline prices from an economic viewpoint, although the government must consider the public welfare after recent price increases on rice, flour and other basic commodities, as well as taxi fares.

Based on the revised floating oil-pricing formula, domestic oil prices will be automatically frozen from further hike if the prices have been hiked by 15 percent from the level recorded since the revised formula was taken into effect in September. Before reaching the threshold, there is still room of NT$0.47 per liter for raising local oil prices.

Meanwhile, Economics Minister Steve R.L. Chen said that after the oil price hike ceiling of 15 percent is reached, it will be suitable timing for the government to determine whether to freeze any price increases, after taking into consideration opinions from various sectors.

Chen said although some opine since CPC Corp.'s earnings have reached the government-set level for the entire year of 2007, the state-run oil firm shouldn't hike its domestic oil prices, but give all its earnings to the national coffers to take care of underprivileged groups, and small to medium-sized enterprises.

He stressed that as part of government efforts to ease inflationary pressure, water and electricity rates have remained unchanged for a long time.