UPDATE 5-Oil prices flat, caught between Venezuela supply concerns and gloomy economic outlook * Venezuela vs U.S. oil production * U.S. sanctions against Venezuela stoke supply concern * Maduro offers opposition talks on Russian TV * Slowing economic growth drags on fuel-demand outlook * U.S., Chinese officials to start trade talks on Wednesday (Recasts, updates prices) SINGAPORE, Jan 30- Oil prices held steady on Wednesday, supported by concerns about supply disruptions following U.S. sanctions on Venezuela's oil industry but pegged back by a darkening outlook for the global economy. U.S. West Texas Intermediate (WTI) crude futures were at $53.30 per barrel at 0748 GMT, virtually unchanged from their last settlement. International Brent crude oil futures were also flat, at $61.32 per barrel.Washington on Monday announced export sanctions against state-owned oil firm Petroleos de Venezuela SA (PDVSA), limiting transactions between U.S. companies that do business with Ve