China Unicom, the mainland's No 2 telecommunications carrier, yesterday sold 368.86 million more shares to meet extra demand. The additional issue boosted the size of the company's initial public offering by HK$5.74 billion. The extra shares lifted the total amount raised by the company to HK$44.06 billion - or US$5.65 billion - almost enough to build a new Chek Lap Kok airport. The company's listing co-sponsors, Morgan Stanley Dean Witter and China International Capital Corp, issued the additional shares under an over-allotment option after receiving a 'moderate oversubscription' from institutions overseas. The successful listing is seen as smoothing the way for other large state-owned mainland companies to follow suit. Beijing is keen to rebuild its state sector by trimming its holdings in most sectors. China Unicom's listing is the biggest initial public offering by a mainland company.