Standard & Poor's has raised the foreign currency corporate credit rating of China Petroleum & Chemical (Sinopec) from BBB minus to BBB, citing an improvement in operations and an increase in oil and gas reserves. But the rating agency said a significantly lower oil price in the second half of this year would put pressure on the H share's bottom line. It cited Sinopec's forecast of a year on year decline in earnings before interest, taxes, depreciation and amortisation in the year to December 31, to about 50 billion yuan (HK$46.8 billion) from 56.8 billion yuan before. Standard & Poor's said the upgrade was based on operational improvements, such as shutdowns of inefficient refineries. The widening of the international benchmarks to which mainland oil-product prices are linked had also given Sinopec greater flexibility to set prices and helped lower the impact of oil-price volatility, the agency said. Earlier this year, Sinopec increased its oil and gas reserves to 3.9 billion of oil equivalent from 3.2 billion barrels, via the acquisition from parent Sinopec Group of China National Star Petroleum. The purchase raised Sinopec's crude oil self-sufficiency to 29 per cent from the 25 per cent previously. Sinopec is an integrated oil and petrochemical company, which explores and produces oil and gas and refines them into petrochemical products.