BANGKOK (AFX-ASIA) – Kim Eng Securities said it still rates PTT Exploration and Production (PTTEP) shares a ‘buy’ on valuation grounds, which it feels is undervalued by the market. Kim Eng Securities noted that the stock is currently trading on a ‘cheap’ price earning ratio of 6.9 times and EV/EBITDA of 5.1 times. Furthermore, PTTEP…