** U.S.-listed shares of oil firms fall premarket, tracking falling oil prices O/R
** Brent crude futures LCOc1 down 0.7% at $64.95/barrel, U.S. West Texas Intermediate crude CLc1 fall 0.4% to $62.23/barrel
** Oil prices fell after Moody's downgraded the U.S. sovereign credit rating and official data showed slowing growth in China's industrial output and retail sales
** Energy majors Chevron CVX.N and Exxon XOM.N down 1.9% and 0.7%, respectively
** APA Corp APA.O down nearly 1%, Devon Energy DVN.N dips 1.4%, ConocoPhillips COP.N falls 2%
** Oilfield service companies Halliburton HAL.N and Baker Hughes BKR.O slip 1.2% and 1.8%, respectively
** Refiners Valero Energy VLO.N and Marathon Petroleum MPC.N down 1% each
(Reporting by Katha Kalia in Bengaluru)
((Katha.Kalia@thomsonreuters.com))