Sept 18 (Reuters) - Britain's Prudential Plc said on Saturday it plans to raise HK$22.5 billion ($2.9 billion) through a concurrent public offer and international share placing on the Hong Kong Stock Exchange.

Prudential said in a statement that it plans to offer 130.8 million new shares, or 5% of its issued share capital, at HK$172 per share, adding that an additional 32.7 million new shares could also be issued.

Life insurer Prudential said it expects to determine the public offer price and the placing price on or around Sept. 25, with trading expected to begin on Oct. 4. ($1 = 7.7818 Hong Kong dollars) (Reporting by Anirudh Saligrama in Bengaluru; Editing by Alexander Smith)