OPEC ministers agreed a new crude production ceiling of 30 million b/d that covers all 12 members, including Libya and Iraq, but does not include individual quotas, ministers and delegates said Wednesday.
The deal effectively legitimizes current freewheeling production and consigns the Oran, Algeria, agreement of December 2008 to the past.
"We have an agreement to maintain the market in balance," Ramirez said as he left the meeting, which took place at OPEC's Vienna secretariat.
Ramirez said all OPEC members would reduce supply to make space for Libya, whose output is recovering after falling to almost zero during this year's uprising against the regime of Moammar Qadhafi.
"We are going to reduce the level of production of each country to make space for Libya," he told reporters.
But Ramirez also said the effort to accommodate Libya's return to the market would be borne mainly by those countries which had boosted supply above previously agreed levels to make up for the shortfall earlier in the year.
"The countries that overproduced have to reduce to make space for Libya," he said.
"Obviously, we are catering for Libya," said Qatari oil minister Mohammed al-Sada as he left the meeting.
UAE oil minister Mohammed Bin Dhaen al-Hamli said OPEC was ready to make space for Libya, but that would be "no cutback" in the short term.
"Everybody knows we are currently producing around 30 million b/d," Hamli said after the meeting.
What remains unclear is how OPEC settled on the 30 million b/d figure. OPEC on Tuesday said it expected demand for OPEC crude next year to average 30.09 million b/d.