The price for crude oil produced by the Organization of the Petroleum Exporting Countries (OPEC) fell by 0.62 dollars Friday, DPA quoted sources of OPEC as saying Monday. One barrel (159 litres) of OPEC-produced crude stood at 111.23 dollars Friday, down from 111.85 dollars on the previous day. OPEC calculates an average basket price based on 13 brands produced by cartel members.