Vienna, May 13 - The basket of 12 crude oils of the Organization of Petroleum Exporting Countries (OPEC) stood a tad lower at $104.21 a barrel Monday, against $104.46 last Friday, according to the OPEC Secretariat.

The new OPEC reference basket comprises Saharan Blend (Algeria), Girassol (Angola), Oriente (Ecuador), Iran Heavy (Iran), Basra Light (Iraq), Kuwait Export (Kuwait), Es Sider (Libya), Bonny Light (Nigeria), Qatar Marine (Qatar), Arab Light (Saudi Arabia), Murban (United Arab Emirates) and Merey (Venezuela). A barrel is equal to 159 litres. (IANS)