Saudi Arabia’s oil minister broke months of silence on Wednesday to speak publicly about the Gulf nation’s stance on the oil market and dismiss claims that it had triggered a “price war”.

Investment in US shale oilfields will fall by a tenth next year – and result in a decline in production – if the oil price continues to trade around $80 a barrel, the world’s energy watchdog has warned.

Oil tumbles to four-year low below $79, awaits OPEC

With less than three weeks to go before OPEC meets in Vienna and the selloff in oil showing few signs of letting up, speculation is mounting the group will take action to try to stem the decline.

A growing list of delayed or cancelled projects, seen by some investors as a healthy move by majors to rein in capital spend after a poor history of returns is working its way through corporate earnings; it has already pummelled the share price of some European suppliers seen as financially fragile.

West Texas Intermediate and Brent oils increased after U.S. employment gains exceeded 200,000 for a ninth month and the jobless rate dropped to a six-year low, bolstering the fuel demand outlook.

WTI for December delivery rose $1.05, or 1.4 percent, to $78.96 a barrel at 9:40 a.m. on the New York Mercantile Exchange. Prices are down 2 percent this week and 20 percent this year.

Petroleo Brasileiro SA (PBR) headed for the longest losing streak in a year as plunging oil prices and currency weakness overshadowed a decision to give the state-run producer some relief from inflation-fighting policies.

The standoff between Russia and the West over Ukraine has increased Europe's quest for alternative suppliers of oil and gas and Canada's exports to Europe have already started to pick up in the last few months.

Brent crude capped a sixth weekly loss, the longest losing streak since 2002, as OPEC boosted production to a 14-month high amid a global surplus.