** S&P 500 energy index .SPNY falls 0.4% as oil prices edge lower

** Brent crude futures LCOc1 down 1.2% at $68.92 a barrel; U.S. West Texas Intermediate $(WTI)$ crude CLc1 falls 1.3% to $67.30 a barrel

** Oil prices fall as market participants assessed U.S. decision to move personnel from Middle East ahead of talks with Iran over the country's nuclear-related activity

** Oil majors Chevron CVX.N and Exxon Mobil XOM.N down 0.7% and 0.6%, respectively

** Halliburton HAL.N, Valero Energy VLO.N and APA APA.O down between 1.7% and 2.4%; among top pct. losers on energy index

** Refiner Marathon Petroleum MPC.N down 1.3%

** Oilfield services firm Baker Hughes BKR.O down 1%

(Reporting by Tanay Dhumal in Bengaluru)

((Tanay.Dhumal@thomsonreuters.com; Twitter: https://twitter.com/TanayDhumal))