BUZZ-Oil and gas companies: Oil prices fall on worries of oversupply

** Oil and gas companies shares down 1-6 pct premarket

** Brent crude oil prices slipped below $59 a barrel afteranother big weekly build in U.S. crude inventories and apossible rise in Saudi output stoked worries about oversupply

** Brent crude down 2.3 pct at $59.14 per barrel at06:55 a.m. ET; U.S. crude down 3.6 pct at $50.28 perbarrel

** Oil producers: Whiting Petroleum Corp down 5.8pct, Oasis Petroleum 4.3 pct, Statoil ASA 3.2pct, Total SA 2 pct, ConocoPhillips 1.7 pct

** Royal Dutch Shell Plc shares down 1.3 pct,Chevron Corp 1.1 pct, Petrobras 1 pct, BP Plc 1 pct

** Oilfield services companies: Schlumberger Ltd down 1.8 pct, Halliburton Co 1.9 pct, Denbury ResourcesInc down 2 pct, Basic Energy Services Inc 2.2pct

** Contract drillers: Seadrill Ltd down 3.4 pct,Transocean Ltd 1.9 pct, Diamond Offshore Drilling Inc 2.6 pct, Nabors Industries Ltd 2 pct, Ensco Plc 2 pct