Oil futures plunged further on Monday to mark their lowest settlements in nearly 7 years, in the aftermath of the decision by the Organization of the Petroleum Exporting Countries last week to keep crude production running at current levels.

January West Texas Intermediate crude dropped $2.32, or 5.8%, to settle at $37.65 a barrel on the New York Mercantile Exchange. That was the largest one-day percentage loss since September.

January Brent crude fell $2.27, or 5.3%, to end at $40.73 a barrel on London’s ICE Futures exchange.

WTI and Brent prices, which each lost about 4.2% last week, haven’t settled at levels this low since February 2009, based on the most-active contracts.

On Friday, WTI crude settled 2.7% lower while Brent futures lost 1.9% after OPEC, at its meeting in Vienna, agreed to maintain a ceiling that reflects “current actual production” even as the market struggles with oversupply.

OPEC previously had a production ceiling of 30 million barrels a day, but members have been producing closer to 31.5 million barrels a day, according to market estimates. Analysts have concluded that the decision essentially legitimizes the cartel’s overproduction.

Still, the low prices do seem to be having an impact on production. Monthly data released Monday by the U.S. government showed that domestic shale-oil output is expected to fall by 116,000 barrels a day to 4.861 million barrels a day in January.

Source: MarketWatch