Caltex has increased the price of petrol by about 41 HK cents a litre, reversing the downward trend of the past seven months. It blamed a 28 per rise in prices in Singapore since mid-December. Caltex petrol will now cost HK$12.99 to HK$13.83 a litre. However, diesel and LPG prices were cut by 18 HK cents a litre and HK$1.82 a kilogram because of falling world prices.