** Oil and gas producers and services providers' shares downas prices fall on fresh signs of oversupply and weak demand
** Brent crude falls to $64.04 a barrel - lowestsince September 2009; U.S. crude falls to $60.88 - lowestsince July 2009
** Exxon Mobil Corp shares down 2.9 pct at $88.76,Chevron Corp down 3.3 pct at $103.48, Hess Corp down 3.9 pct at $69.33
** Smaller rivals Penn West Petroleum Ltd down 13.2pct at $2.31; Approach Resources Inc down 9.4 pct at$5.88; Energy XXI Ltd down 8.6 pct at $2.92
** Oilfield services and equipment providers SchlumbergerLtd down 3.2 pct at $82.78, Halliburton Co down3 pct at $33.26, National-Oilwell Varco Inc down 2.8 pctat $63.10