(EnergyAsia, March 2) — Thai state energy company PTT Public Company Limited has unveiled a five-year investment plan to 2010 worth Bt238.79 billion. (US$1=40 baht).   Its key investments include the third natural gas pipeline, the Sainoi-North and South power plant gas pipeline, the Wangnoi Kaengkoi gas pipeline, upgrades to gas separation plants unit 2,…