Brent crude fell 2.1 percent to $39.88 a barrel at 1:45 p.m. London time Tuesday, the lowest since Feb. 20, 2009.

Oil has slumped about 40 percent since Saudi Arabia led the Organization of Petroleum Exporting Countries’ decision a year ago to maintain output and defend market share by pressuring higher-cost producers. At a meeting on Dec. 4 in Vienna, the group set aside its production target of 30 million barrels and endorsed current output of about 31.5 million. The lack of any limit on OPEC supplies could lift the lid on millions of barrels of additional crude from countries including Iran next year.

“Forty dollars ought to be the floor of Brent crude’s short-term range,” said Giovanni Staunovo, an analyst at UBS Group AG in Zurich. “Current prices should cause sufficient pain on non-OPEC producers, triggering further cuts in spending and investment. And the $40 mark has some technical significance as a round number.”

OPEC had a collective target of 30 million barrels a day since 2012. Most of the market “doesn’t have any ceiling” on production, Iraqi Oil Minister Adel Abdul Mahdi told reporters after the meeting in Vienna. “Americans don’t have any ceiling. Russians don’t have any ceiling. Why should OPEC have a ceiling?”

After OPEC’s decision, “everyone does whatever they want,” according to Iranian Oil Minister Bijan Namdar Zanganeh. The Persian Gulf nation is seeking to boost crude exports by as much as 1 million barrels a day next year when international sanctions over its nuclear program are removed.

The oil market has an oversupply of at least 1.5 million barrels a day, Venezuelan Oil Minister Eulogio Del Pino told reporters before the meeting. If OPEC failed to curb this surplus by cutting production, it would result in a “catastrophe” for the market and potentially another $20 drop in prices, he said.