Dec. 14 (Bloomberg) -- OPEC, the producer of 40 percent of the world's oil, approved a 1.9 percent production cut and accepted Angola as its first new member in 31 years to gain greater control over global crude supplies.

Output will be reduced by 500,000 barrels a day as of Feb. 1, OPEC President Edmund Daukoru said today in Abuja, Nigeria. The cut is in addition to the 1.2 million barrel-a-day reduction agreed upon by the Organization of Petroleum Exporting Countries on Oct. 20 in Doha, Qatar.

Oil prices today had their biggest gain in two weeks, advancing 2.3 percent, and rebounding from a four-month slide from a July record. Angola, Africa's fastest-growing oil producer, will bring an additional 1.4 million barrels a day under OPEC's control.

``OPEC is sending a message that it is trying to control supply and keep a floor under the price,'' said Mike Wittner, the London-based head of energy market research at Calyon, a unit of Credit Agricole SA. ``It's a compromise between the countries that wanted a cut and those that wanted a roll-over.''

Crude today rose as high as $62.80 a barrel on the New York Mercantile Exchange, the highest since Dec. 8. It traded up $1.13 at $62.50 as of 2:28 p.m. in New York. Prices also climbed earlier after a refinery explosion in Canada.

The latest OPEC supply cut will take effect about seven weeks before the end of the northern hemisphere winter, when demand for heating fuels typically starts to decline.

`Short-Term Bullish'

Crude oil has averaged about $60 since the previous meeting and rose yesterday on speculation the producer group's meeting would result in lower supplies. ``The decision is short-term bullish but it won't push prices up by several dollars,'' said Wittner.

Today's announced cuts should be enough to stabilize oil prices this year, Algeria's oil minister, Chakib Khelil, said today in an interview.

Oil has been above $50 a barrel for the past 18 months. The retreat from July's record occurred as tensions eased between the West and Iran over the Islamic country's nuclear research program. A benign hurricane season in the oil-producing U.S. Gulf of Mexico also helped drive down the price of crude.

Not Bound

Saudi Arabia's Oil Minister Ali al-Naimi said OPEC members are about ``80 percent'' compliant with the 1.2 million barrels a day cut agreed upon in Doha. ``Compliance is quite good, otherwise why would inventories come down,'' said Naimi, talking to reporters in Abuja. Merrill Lynch's & Co's head of commodities research Francisco Blanch said earlier this week that OPEC has completed ``at least half'' of the Doha cuts.

Angola's membership will be effective from Jan. 1, said Daukoru, who is also Nigeria's oil minister. Angola won't be bound by today's agreement until March 1, he said.

The African nation will be the first country to join OPEC since Gabon, which became a member in 1975 only to exit in 1994. Nigeria, the group's fifth-largest producer, was the last existing member to join, in 1971, according to the group's Web site.

Angola will rival Algeria as the ninth-largest producer in OPEC. Its entry would make the country subject to the group's limits for crude output, helping it influence prices. The African nation has increased output by 18 percent to more than 1.4 million barrels a day this year.

To contact the reporters on this story: Stephen Voss in Abuja through the London newsroom 2166 or sev@bloomberg.net; Julie Ziegler in Abuja through the London newsroom at jziegler@bloomberg.net

Last Updated: December 14, 2006 14:35 EST