BANGKOK (AFX-ASIA) – Merrill Lynch Phatra Securities has reiterated its “buy” rating on PTT Exploration and Production (PTTEP), with a 12-month price target of 240 baht, after the company signed a gas sale and purchase agreement with its parent PTT PLC. (US$1=40 baht). PTTEP and its joint venture partners in the Arthit project last week…