“We are seeing record flows from clients wanting to invest in Vietnam and the dialogue with domestic companies wanting to expand has never been busier,” said Natasha Ansell, Citigroup’s country head for Vietnam. Vietnam’s stock exchange is preparing for its biggest initial public offering after bankers selling mall operator Vincom found a way around a technical restriction that prevented big IPOs in the past. Vincom will raise between $620m and $680m in a listing in November — more than twice as much as any previous IPO on the Ho Chi Minh stock exchange — based on a pricing range agreed on Monday. The IPO promises a windfall for private equity group Warburg Pincus. The price range would mean that Warburg Pincus’s 4.8tn dong ($211m) investment will more than double in value after the IPO, with the group expected to reduce its ownership from 15.2 per cent to 4.89 per cent. Credit Suisse’s Singapore branch is set to achieve a similar gain on its 1.6tn dong ($70m) investment, along with local investors.