BANGKOK (AFX-ASIA) – UOB Kay Hian Securities (Thailand) has given PTT Plc a ‘buy’ rating based on the company’s 2002 dividend payment of 2.85 baht per share, representing a yield of 6.8%, the brokerage said in a report. (US$1=42 baht). PTT’s ex-dividend date is April 2. The report added PTT’s current market price is still…