Nokia named the man who led a turnaround at its main telecoms network business as its new chief executive on Tuesday, boosting investors’ confidence in the future of the company following the sale of its once-dominant handset arm. The Finnish company, which completed the €5.6 billion ($7.8 billion) deal to sell its mobile handset business to Microsoft on Friday, said Rajeev Suri would become CEO on May 1, replacing Microsoft-bound Stephen Elop.