** Shares of U.S. energy companies gain premarket, tracking higher crude prices as conflict in the Middle East kept shipping and energy exports through the vital Strait of Hormuz halted O/R

** Brent Crude futures LCOc1 up 4.4% at $89.12 per barrel; while U.S. West Texas Intermediate CLc1 gains 6.2% to $86.06/barrel

** "Volatility remains high and physical markets are getting tighter...We'd anticipate prices to continue to rise with no obvious triggers for an easing of the risks to supply on horizon," Panmure Liberum analyst Ashley Kelty said

** Energy majors Exxon Mobil XOM.N gains 1.7% and Chevron CVX.N rises 1.6%

** Oil and gas producers: Diamondback Energy FANG.O, APA Corp APA.O, Occidental Petroleum OXY.N and Devon Energy DVN.N rise between 1.9% and 3.1%

** Oilfield services companies SLB SLB.N and Halliburton HAL.N gain 1.2% each

** Refiners: Marathon Petroleum MPC.N up 1.7%, Valero Energy VLO.N gains 1.4% and Phillips 66 PSX.N rises 1.2%

(Reporting by Sumit Saha in Bengaluru)

((Sumit.Saha@thomsonreuters.com;))