When Malaysian civil engineering contractor BBSB International listed in Hong Kong last month, its offering was oversubscribed by a factor of nearly 11,000, and its shares rose more than fivefold from their offer price of HK$0.60 on the morning of their trading debut. BBSB is one of several non-Chinese companies that have flocked to Hong Kong to list recently, and banks expect more to follow this year as the city’s initial public offering (IPO) market booms. While New York and London used to be...