Vienna, Ramadan 17, 1439, Jun 1, 2018, SPA -- The reference price of OPEC basket of 14 crudes stood, at $75.17 a barrel on Thursday, 31st May 2018, compared to $73.72 the previous day, according to OPEC Secretariat calculations. The basket is a blend that includes a mix of crudes from OPEC member states and serves as an exclusive benchmark. -- SPA 19:47 LOCAL TIME 16:47 GMT 0010 www.spa.gov.sa/w697359