The price for crude oil produced by the Organization of the Petroleum Exporting Countries (OPEC) climbed 18 cents on Thursday, OPEC said Friday, according to DPA. One barrel (159 litres) of crudes from OPEC's reference basket stood at 118.95 dollars on Thursday, compared with 118.78 dollars the previous day. In its latest monthly oil market report, released on Thursday, OPEC revised its 2008 demand growth forecast down by 40,000 barrels per day to 1.16 million barrels per day. The 13-member cartes is responsible for about 40 per cent of the global crude output.