Verizon CEO Hans Vestberg initiated a review of the operator’s top leadership and is expected to select a new executive team to lead the company’s 5G effort by the end of the year, Bloomberg reported.

Sources told the news outlet the CEO is interviewing Verizon’s top 300 leaders, adding not all are expected to keep their jobs as Vestberg repositions the company to eliminate service silos and sell unified product sets. CSO Rima Qureshi, human resources head Marc Reed and former CEO Lowell McAdam are reportedly helping Vestberg with the evaluations.

Vestberg joined Verizon as CTO in May 2017 and took over from McAdam as CEO in August.

The move comes as Verizon aims to deliver promised 5G service rollouts across the country and trim its workforce in a bid to cut costs.

In September, Verizon launched a voluntary buyout offer for just over a quarter of its employees, giving them until mid-November to decide whether to accept the severance package. It also traded nearly 2,500 additional staff to Infosys as part of a $700 billion deal with the outsourcing company.

Earlier this month, Verizon flipped the switch on its first deployments of fixed wireless access 5G residential broadband in four US cities. Executives previously stated the company is planning to rapidly follow those launches with mobile 5G deployments in early 2019.