TAIPEI (CNA) -- Taiwan's two major fuel suppliers on Sunday announced increases in fuel prices for the coming week, citing tensions in the Middle East and a halt in oil drilling operations in the Gulf of Mexico.



State-run oil refiner CPC Corp. Taiwan said it will raise gasoline and diesel prices by NT$0.40 per liter and NT$0.50 per liter, respectively, beginning midnight Sunday.



With the adjustment, retail prices at CPC gas stations will be NT$27.60 (US$0.88) per liter for 92 octane unleaded, NT$29.10 per liter for 95 octane unleaded, NT$31.10 per liter for 98 octane unleaded, and NT$25.60 per liter for super diesel.



CPC adjusts its fuel prices weekly based on changes in crude oil prices calculated using a weighted oil price formula composed of 70 percent Dubai crude and 30 percent Brent crude.



Based on that formula, the price of crude rose US$1.98 during the past week to US$64.84 per barrel due to ongoing tensions between the U.S. and Iran.



Other factors affecting international oil prices included the temporary stoppage of drilling operations in oil fields along the Gulf of Mexico due to Tropical Storm Barry and a decrease in U.S. crude inventories.



The increase in crude prices was fully reflected in the retail price hikes.



Under Taiwan's system, increases in crude oil prices cannot push local fuel prices above those of any of the country's major industrial competitors -- Japan, South Korea, Hong Kong and Singapore -- meaning CPC has been unable at times to pass on hikes in crude prices to consumers.



That use of a price ceiling has forced CPC to absorb NT$1.8 billion in crude price increases in the first six months of 2019.



Meanwhile, CPC's main competitor, Formosa Petrochemical Corp. (FPCC), announced identical price adjustments for its gasoline and diesel products in a statement, to take effect at 1 a.m. Monday.



Prices at FPCC gas stations will be NT$27.60 per liter for 92 octane unleaded, NT$29.00 per liter for 95 octane unleaded, NT$31.10 per liter for 98 octane unleaded, and NT$25.40 per liter for diesel.