Energy companies gain as investors weigh returning supply, US-Iran talks

S&P 500 energy index .SPNY gains 1.3% as oil prices edge higher

Brent crude LCOc1 futures up 0.7% at $66.75/barrel; U.S. West Texas Intermediate (WTI) crude futures CLc1 rise 0.9% to $62.70/barrel

Prices rise as market participants considered the global supply outlook and the possibility of a de-escalation in U.S.-Iran tensions O/R

Oil majors Exxon Mobil XOM.N and Chevron CVX.N gain 2.4% and 1.1%, respectively

ONEOK OKE.N, Williams Companies WMB.N, ConocoPhillips COP.N and Kinder Morgan KMI.N among biggest percentage gainers on the energy index, up between 1.7% and 2.6%

Meanwhile, refiners Phillips 66 PSX.N gains marginally and Valero Energy VLO.N rises 2.4%

Oilfield services companies SLB SLB.N rises ~2% and Baker Hughes BKR.O up marginally