** Shares of U.S. oil and gas companies fall premarket, tracking a decline in crude prices O/R

** Both Brent crude futures LCOc1 and U.S. West Texas Intermediate crude CLc1 slipped 4.2% to $63.71/barrel and $59.39/barrel, respectively

** Crude prices fall after U.S. President Donald Trump says killings of protesters in Iran are stopping, easing fears of U.S. interventions and supply disruptions

** Exxon Mobil XOM.N down 0.9%; Chevron CVX.N falls 0.7%

** Oil and gas producers Devon Energy DVN.N, Occidental Petroleum OXY.N, APA Corp APA.O and EOG Resources EOG.N decline between 0.8% and 1.6%

** Oilfield services companies SLB SLB.N and Halliburton HAL.N down 0.8% each

** Refiner Marathon Petroleum MPC.N down 0.8%

(Reporting by Sumit Saha in Bengaluru)

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