Billionaire Guo Guangchang, chairman of Shanghai's Fosun International, is seeking to expand the company's US commercial real estate investments after the acquisition of New York's 1 Chase Manhattan Plaza. Fosun International, the investment arm of the mainland's biggest closely held industrial group, was interested in buying more properties in New York and other "gateway" cities such as San Francisco, Guo said. The company is considering apartments, hotels and offices. "We don't have a fixed number we want to invest," Guo said. "We think in terms of long-term opportunities." Fosun International bought the 2.2 million square foot Chase Manhattan tower for US$725 million. It is the biggest purchase of a New York building by a mainland firm and caps a year in which Chinese investors made some of the city's most high-profile real estate deals. Buyers include the family of Zhang Xin, the billionaire co-founder of Soho China, which purchased a stake in midtown Manhattan's General Motors Building; and Shanghai-based, state-owned developer Greenland, which agreed to acquire a 70 per cent share of Atlantic Yards, a residential and commercial project in Brooklyn. Guo's fortune has jumped 58 per cent to US$4.1 billion this year, according to the Bloomberg Billionaires Index. His conglomerate is investing overseas as it seeks to diversify its holdings, which include property, mining and drugs. Fosun International, which owns a stake in Greek duty-free store operator and jewellery-maker Folli Follie, won approval in July from regulators to take over French resort operator Club Mediterranee with Axa Private Equity. It also agreed in September to buy a stake in Italian suit-maker Raffaele Caruso. On the mainland, the Shanghai-based firm sold 9.1 billion yuan (HK$11.54 billion) of properties in the first half of 2013 through real estate unit Forte Land, an increase of 78 per cent from a year earlier. Fosun International studied the New York real estate market for four years, Guo said. He described it as an "honour" to own 1 Chase Manhattan Plaza, the building David Rockefeller developed as part of a campaign to preserve downtown's relevance as a financial capital. "The most important is the market research about the building, but Mr David Rockefeller's role is a plus," he said. Fosun International understood the complexities of the lower Manhattan office market, said Alain Chang, vice-president of Fosun Property. Contraction in the financial services industry has left more than 6 million sqft of vacancies.