KARACHI - The Pakistan State Oil (PSO) has decreased the High Sulphur Furnace Oil (HSFO) prices by Rs1400/ton (2.8 per cent month-on-month basis) to Rs 48378/ton from Rs 49778/ton. However, the decreased prices are still up Rs22484/tons with the positive 87 per cent on year-on-year basis in April, 2010. According to the official spokesperson of PSO, the prices decrease is made due to the current lower prices of the HSFO in the international market. But the prices might be up in the coming days depending on the demand of the fuel. 'The three vessels of HSFO were purchased on the low prices from the international market that is why the prices have been decreased by the company, she added.