(Updates) ** Shares of oil companies decline further in morning trading after eight OPEC+ countries announced they would advance their plan for oil output hikes
* OPEC+ will increase output by 411,000 barrels per day in May
** Brent futures fall 6.1% to $70.36/bbl; U.S. West Texas Intermediate crude futures decline 6.6% to $66.99/bbl by 1344 GMT (09:44 a.m. ET)
** U.S. oil majors Exxon Mobil down 3%, while Chevron falls 3.8%
** Oil and gas producer Occidental Petroleum down 6%, while oilfield services company Halliburton declines 7.2%
** Refiner Marathon Petroleum down 7.8%, while Valero down 8%
** U.S. President Donald Trump on Wednesday announced sweeping new tariffs, which investors worry will inflame a global trade war and limit fuel demand
** Import of oil, gas and refined products exempted from the new tariffs – White House
(Reporting by Arunima Kumar and Seher Dareen in Bengaluru)