Caltex has announced its steepest rise in pump prices for unleaded petrol and diesel since the Gulf War. The move, effective from midnight last night, increased prices of Techron and Superon unleaded petrol by five per cent to $10.34 and $11 a litre respectively. The price of diesel rose by seven per cent from $5.59 to $5.99 a litre. Liquified petroleum gas prices were unaffected. Albert Kwok, general manager of the retail business unit at Caltex, said the decision was attributed to rising import costs. 'Crude oil prices have more than doubled since January and we have to reflect this in our pump prices. 'Our price adjustments offset only part of the increased import costs we face as we are not trying to compensate for all previous losses we've incurred.' Mr Kwok said Caltex had held off price increases since the beginning of the year by streamlining its operations. He said the company had taken customers' needs into account but the increases were inevitable as it had to ensure pump prices were in line with the real costs of its products. Crude oil is trading at about US$23 (HK$179) per barrel, up from US$10 in January.