HSBC said today it planned to privatise Hong Kong's Hang Seng Bank in a deal worth HK$106.1 billion ($13.63 billion) after its majority-held subsidiary has come under fire for its performance and exposure to faltering property markets in the city and mainland China.HSBC will offer HK$155 per share for the 36.5% of shares it does not already own, giving Hang Seng Bank a total valuation of $37 billion.Hang Seng Bank shares surged to as high as HK$168 in early trading before retreating to HK$150.3 by midday, u ...