SoftBank Corp., the Tokyo-based company that owns 80 percent of Sprint, has hired a Google executive with former ties to T-Mobile as its new vice chairman. Nikesh Arora, the new hire, first joined T-Mobile’s parent company, Deutsche Telekom, in 1999. He eventually became T-Mobile Europe’s chief marketing officer and served on its management board, and he was most recently chief business officer at Google. Arora will report directly to founder and chief executive Masayoshi Son, and some say the hire may be a logistical move in preparation for a long-rumored merger between T-Mobile US and Sprint. SoftBank said Arora would join the company in October as chief executive of a new business called SoftBank Internet and Media Inc.