The new OPEC Reference Basket of Crudes (ORB) is made up of the following: Saharan Blend (Algeria), Girassol (Angola), Oriente (Ecuador), Minas (Indonesia), Iran Heavy (Islamic Republic of Iran), Basra Light (Iraq), Kuwait Export (Kuwait), Es Sider (Libya), Bonny Light (Nigeria), Qatar Marine (Qatar), Arab Light (Saudi Arabia), Murban (UAE) and Merey (Venezuela).
Meanwhile, BBC reports that many Asian markets fell on Tuesday as the decline in the oil price appeared to weigh on investor sentiment.
In Japan, the benchmark Nikkei 225 closed down 2.4% at 15,732.82, the sixth session in a row that the index has fallen.
In South Korea, the Kospi index closed down 0.8% at 1,962.74, the lowest close in a month.
US stocks ended lower on Monday after the price of US crude oil fell 3% in New York trade.
The drop extended falls from the previous two trading sessions, as hopes faded that oil producers would agree to curb production at their meeting on 17 April.
Oil prices hit a peak of $115-a-barrel in June 2014, but have plunged by more than 70% since then because of oversupply and sluggish demand.
The oil producers’ meeting later this month will take place in the Qatari capital, Doha. It will involve Opec and non-Opec members and will discuss freezing supply at January levels to help push the oil price back up.