SHANGHAI, Oct 9 (Reuters) - Shares in Hong Kong-listed Haitong international Securities Group nearly doubled on Monday on a privatisation plan by Shanghai-based Haitong Securities.

Haitong Securities is offering up to HK$3.5 billion ($443 million) for all the shares it does not own in its Hong Kong-listed unit, Haitong International Securities, to take it private.

Haitong Securities currently owns 73.4% of the investment banking arm. The broker said it will offer HK$1.52 per share for 2.28 billion outstanding shares, a 114% premium over Haitong International Securities' last closing price of HK$0.71.

Haitong international Securities surged 97% to HK$1.4 in Monday afternoon trade.

(Reporting by Shanghai Newsroom; Editing by Kim Coghill)