Producers are reducing their output to prop-up prices
Oil prices slipped to just over the $51 per barrel mark for Brent Crude last night - despite the decision by OPEC to maintain current production cuts across its member countries of 1.8m barrels per day for the next nine months.
There had been speculation that the group would introduce greater production cuts, over a longer period of time.
"We considered various scenarios from six to nine to 12 months and we even considered options for higher cuts," said Saudi Arabia's energy minister, Khalid al-Falih after the meeting.
"All indications are solid that a nine-month extension is the optimum, and should bring us to within the five-year average of inventories by the end of the year," he added.
OPEC reached an agreement with 11 other oil producers - including Russia - to reduce production in December of last year.
That led to a 2% fall in global production and was an attempt to prop up oil prices.