The head of OPEC said on Sunday the group had no target price for oil, signalling no change to a policy to maintain production levels which has contributed to sharp falls in the price of crude, unnerving global markets.

Repsol, the Spanish oil group, is aiming to acquire Talisman Energy of Canada, in a deal that would value the target’s equity at up to $8bn

Mexico has unveiled long-awaited initial contract terms for the first 14 oil and gas areas it is auctioning in a historic tender round starting next year. They impose a ban on oil majors teaming up to bid and a five-block limit on bids from any company or consortium.

Halliburton Co. , the world’s second-largest oilfield-services company, said Thursday it will lay off 1,000 employees outside the U.S.

Iran's President Hassan Rouhani said Wednesday that the sharp fall in global oil prices is the result of "treachery," in an apparent reference to regional rival Saudi Arabia, which opposed production cuts.

Global demand for OPEC crude in 2015 is expected to fall to the lowest level in more than a decade and far below current output, the group said on Wednesday, pointing to a hefty supply surplus without OPEC output cuts or a slowdown in the U.S. shale boom.

Plunging oil prices look set to trigger another wave of industry consolidation after a decade when mega-deals were scarce, but investors want to see mergers that can squeeze out cost savings and only after a lavish dividend is paid.

The next few months are likely to be chaotic for the global energy industry

Renewed pressure on crude oil prices on Monday weighed heavily on the shares and bonds sold by US energy companies

The main Saudi concern is to protect market share.