SoftBank Group Corp. named Marcelo Claure chief operating officer, elevating Sprint Corp.'s top executive into a broader role after he negotiated a merger between the U.S. wireless operator and T-Mobile U.S. Inc.

As part of the transition, Claure, 47, will become executive chairman at Sprint and cede the CEO post to Michel Combes, currently the chief financial officer. In his new roles, Claure will continue to work on the Sprint/T-Mobile combination, which still faces a challenging regulatory review in Washington before it can close.

At SoftBank, Claure will become COO under founder Masayoshi Son and focus on improving execution in and among the company's portfolio of businesses. SoftBank has used cash from its Japanese operations to buy stake in companies such as Sprint, Yahoo Japan Corp. and Alibaba Group Holding Ltd. It also set up the largest-ever technology investment fund and made investments in startups from ride-hailing pioneers Uber Technologies Inc. and Didi Chuxing to Indian e-commerce leader Flipkart Online Services Pvt. and satellite provider OneWeb.