Government has increased excise duty on petrol and diesel by 1 rupee and 50 paise a litre. However, the increase will not affect the retail price of petrol and diesel as oil companies offset the hike against an expected reduction on account of falling global oil rates. The duty hike will boost government revenue by about 13 thousand crore rupees and help contain budget deficit. Indian Oil Corporation, Chairman B Ashok said, the fall in international oil prices had resulted in six consecutive reduction in petrol prices since August and two in diesel in the last one month. Global crude oil prices continued their slide. Brent crude oil futures fell more than one dollar, to a four-year low of 79.35 dollars a barrel, today, after Chinese data showed a further slowdown in activity in the world's biggest energy consumer, and Saudi Arabia remained silent about a possible cut in production. Ministers from the OPEC are to meet in Vienna on November 27, to decide on how to respond to a 30 percent fall in oil prices over the last five months.