Billionaire Masayoshi Son told Softbank Corp. investors Friday how he plans to use the purchase of Sprint Nextel Corp. to transform Japan's No. 3 mobile carrier into the world's No. 1.

At the company's annual meeting, Son is working to convince shareholders his $21.6 billion bid for Sprint will generate growth for the Tokyo-based company as it faces a shrinking population at home. Softbank inched closer to the acquisition after Dish Network Corp. passed on making a new offer by the U.S. carrier's deadline earlier this week.

The global ambitions of Son, 55, who invited his Twitter followers to attend even if they weren't Softbank shareholders, are also fueling Sprint's separate offer for full control of Clearwire Corp. The broadband company, already majority-owned by Sprint, controls valuable wireless airwaves that Softbank needs to roll out a fourth-generation network in the U.S. to challenge leaders Verizon Wireless and AT&T Inc.