SoftBank Corp CEO Masayoshi Son said on Friday he was confident his company's acquisition of Sprint Nextel Corp will be completed in early July after rival bidder Dish Network Corp failed to make a counter move this week. SoftBank, a Japanese mobile network operator, is heading into the home stretch as it tries to push through Japan's biggest ever acquisition, while aggressive dealmaker Dish has loomed as a potential spoiler with rival offers for Sprint and its Clearwire Corp subsidiary. Son, SoftBank's billionaire founder, said Dish's failure to raise its offer for Sprint before a deadline early this week brought the Japanese company closer to sealing the $21.6 billion deal, but warned that its U.S. rival could make a surprise move before a Sprint shareholders' meeting on June 25. "We don't know what could happen before the meeting but we took a big step forward after Dish missed the deadline to make a new proposal," Son told an annual sharehol