Hong Kong tycoon Li Ka-shing launched a multibillion-dollar bid for an Australian infrastructure group, a move likely to test Canberra’s openness to overseas investment in a climate of heated debate about foreign takeovers, according to The Wall Street Journal. Mr. Li’s Cheung Kong Infrastructure Holdings bid about 7.3 billion Australian dollars (US$5.4 billion) for Duet Group, a pipeline operator and power distributor, marking another attempt by the business magnate to strengthen his infrastructure flagship’s position in Australia. In a statement Monday, Duet said its board was evaluating the unsolicited cash offer of A$3 a share. The board plans to decide this week whether to allow Cheung Kong to conduct due diligence, a company spokesman said. A takeover would be subject to regulatory approval in Australia, including from the Foreign Investment Review Board.