Futures dropped as much as 3 percent in New York after climbing 16 percent the previous seven sessions. Iraq will boost crude shipments by about 5 percent in the next few days following an agreement to resume exports from three oil fields in Kirkuk. The Niger Delta Avengers declared an end to attacks on oil infrastructure and will conduct talks with the government, according to a statement on a website that says it represents the group.

Oil had entered a bull market on Thursday, having climbed more than 20 percent since dipping below $40 a barrel earlier in the month. Speculation that informal OPEC talks next month may lead to action to stabilize the market had pushed prices higher, yet some oil-producing nations may be reluctant to cap output as crude’s two-year slump continues to erode revenue. 

“Because of the fiscal position many oil producers find themselves in, they all desperately want to produce more volume,” Stephen King, senior economic adviser to HSBC Holdings Plc in London, said in a Bloomberg Television interview. “A freeze in itself would be very good news for the oil market. The difficulty is trying to enforce a freeze in any particularly credible way.”

West Texas Intermediate for September delivery, which expires Monday, slid as much as $1.43 to $47.09 a barrel on the New York Mercantile Exchange. The contract rose 30 cents on Friday to close at $48.52 for a seventh day of gains, the longest run since July 2012. The more-active October future was down $1.41 at $47.70 as of 11:49 a.m. London time. Total volume traded was about 22 percent above the 100-day average.

Brent for October settlement dropped 3.2 percent to $49.25 a barrel on the London-based ICE Futures Europe exchange, trading at a premium of $1.55 to WTI for the same month. The global benchmark crude slipped 1 cent on Friday to close at $50.88.

Iraq will increase exports by about 150,000 barrels a day as shipments resume from the Baba Gorgor, Jambour and Khabbaz fields, Fouad Hussein, a member of the oil and energy committee of the Kirkuk provincial council, said by phone Sunday. The nation is the second-biggest OPEC producer, pumping 4.36 million barrels a day last month, according to data compiled by Bloomberg.

Oil-market news:

• Nigerian militants said they will cease hostilities in the Niger Delta “against all interest of the multinational oil corporations,” to support talks with the government, according to the statement.
• Eni SpA Chief Executive Officer Claudio Descalzi said in a Bloomberg Television interview that he favors OPEC freezing output.
• Morgan Stanley said it continues to view “a meaningful OPEC production agreement as highly unlikely.”
• Hedge funds trimmed their short position in WTI by 56,907 futures and options during the week ended Aug. 16, the most in data going back to 2006, according to the Commodity Futures Trading Commission.
• U.S. drillers added rigs for an eighth week, the longest run since April 2014, according to Baker Hughes Inc. data on Friday.