Sprint Nextel has finally won the backing of major Clearwire investors with a new offer of $5 a share for the stake that it does not already own. The new bid tops DISH's offer of $4.40 a share and could leave the satellite provider once again searching for partners to enter the wireless arena. The development left SoftBank CEO Masayoshi Son increasingly confident that the Japanese carrier will close its 78% purchase of Sprint next month once the U.S. telecom's shareholders approve the deal on Tuesday. Speaking today at SoftBank's annual meeting, Son predicted that investing $40 billion in Sprint would drive SoftBank from its No. 3 slot in Japan into the position of global leader.