HONG KONG (AFX-ASIA) – Citigroup has downgraded its recommendation for Hong Kong-listed Beijing Datang Power Generation Co Ltd shares to “hold” from “buy”, reflecting modest 12-month total returns of 5.4% as the stock nears its target price of HK$4.75 per share. (US$1=HK$7.87) Citigroup said Beijing Datang’s current stock price of HK$4.65 is pushing historical extremes…