Eleven non-OPEC oil-producing countries have agreed to slash their output by 558,000 barrels per day (bpd), following OPEC's recent decision to cut its own output, OPEC President Mohammed al-Sada said on Saturday.

The newly agreed cut was lower than a figure cited earlier by the Nigerian oil ministry, and also lower than the target of 600,000 that the Organization of the Petroleum Exporting Countries (OPEC) had envisioned for countries outside its group.

OPEC decided last week to reduce its output by 1.2 million bpd from January to boost the currently low prices and to increase their government revenues.

"I believe that this is a truly historic event," said Russian Energy Minister Alexander Novak, who headed the group of non-OPEC countries. He pointed out that the OPEC and non-OPEC countries represented at the output reduction talks in Vienna account for more than half of global supplies.

The announcement came after OPEC member states met with Russia and other non-OPEC countries in Vienna for talks on production cuts.

The 11 non-OPEC countries taking part in the agreement are: Azerbaijan, Bahrain, Brunei, Equatorial Guinea, Kazakhstan, Malaysia, Mexico, Oman, Russia, Sudan and South Sudan.

It remains to be seen whether the cutbacks will do much to raise prices, given that OPEC members' track record of exceeding agreed-upon production quotas.

Oil fell from over $90 per barrel in early 2014 to as low as $40 earlier this year.

Oil closed at $51.58 on Friday, up 6 percent since the OPEC production cut was announced.