MELBOURNE, July 13 (Reuters) - Shares in Australia's biggest float in nearly four years, oil refiner and marketer Viva Energy , made a disappointing debut on Friday, ending their first day 4 percent below the issue price.

The Vaca Muerta play in Patagonia is one of the world's largest reserves of unconventional hydrocarbons.

BUENOS AIRES, July 13 (Reuters) - Argentina plans to include new companies in a 2017 pact among oil producers, workers and the government in an effort to boost competitiveness in the Vaca Muerta shale play, the country's oil rig flanges gulf coast production minister told Reuters on Friday.

A subsidiary of Weatherford International plc has signed a definitive agreement with ADES International Holding Ltd for the sale of Weatherford's land drilling rig operations in Algeria, Kuwait and Saudi Arabia, as well as two idle land rigs in Iraq, for an aggregate cash purchase price of $287.5 million.

Premier Oil confirms that its board has approved the Tolmount gas project.

Premier Oil confirmed Thursday that its board has approved the Tolmount gas project and announced that formal partner sanction is scheduled for the third quarter.

Newest proposed tariffs would affect $200 billion in Chinese imports to the United States.

In the latest chapter of the trade dispute between the U.S.

Oil steadied on Thursday after taking a wild ride.

NEW YORK, July 12 (Reuters) - Stock markets around the world bounced back on Thursday, with U.S.

(Bloomberg) -- The prospects for a massive gas gulf coast oil rig export plant on Canada's Pacific Coast are looking bright, according to executives of service companies that would have a hand in supporting the facility.

BASRA, Iraq, July 12 (Reuters) - Iraqi police fired into the air to disperse protesters demanding jobs and better public services at one of three demonstrations outside major oilfields in the southern oil hub of Basra on Thursday, police sources said.