Shares of oil and gas company Chesapeake Energy Corp. slumped 4.4% toward a six-month low in afternoon trading Friday, despite a bump in crude oil prices, as longer-term concerns over global oil demand helped set off a broad selloff in the energy sector. The SPDR Energy Select Sector ETF shed 0.8%, with 28 of 29 components losing ground, while the S&P 500 eased 0.3%. Among the ETF's more-active components, shares of Halliburton Co. lost 2.1%, Schlumberger Ltd. declined 3.0%, Exxon Mobil Corp. gave up 0.5%, Marathon Oil Corp. slid 2.3% and Occidental Petroleum Corp. fell 0.7%. Crude oil futures rose 0.8%, after settling up 2.2% on Thursday. Meanwhile, the International Energy Agency cut its 2019 oil demand forecast for a second-straight month, citing a slowing in the global economy.