Former Brasil Telecom, Oi exec Roberto Rittes to replace Francisco Valim.

NII Holdings this week named Roberto Rittes as the new chief executive of its Nextel Brazil unit.

Rittes joins from private equity firm H.I.G. Capital, where he served as a principal. He has also held senior roles at Brasil Telecom, and Oi’s mobile payments arm, Oi Paggo.

"We are excited to have Roberto join us in leading our focus on growing our 3G and LTE business by attracting and retaining customers who value the high quality wireless services we offer," said NII Holdings CEO Steve Shindler, in a statement on Tuesday.

Rittes replaces Francisco Valim, the former Oi CEO who joined Nextel Brazil in August 2015.

"I want to thank Francisco for the tremendous efforts in leading the turnaround of our business in Brazil. His expertise in transforming companies and managing organisational change resulted in a significant improvement in our operations, leaving solid foundations on which to keep building," said Shindler.

Brazil is NII Holdings’ sole market, having sold its operations in Argentina and Mexico amid its bankruptcy restructuring in 2015. Before entering Chapter 11 in 2014, NII sold off its units in Chile and Peru.

Nextel is very much the underdog in Brazil.

According to regulator Anatel, the company had 2.60 million active connections at the end of January. By comparison, market leader Vivo had 73.90 million connections, while second-placed TIM Brasil had 62.82 million. Claro came a close third with 60.17 million connections, followed by fourth-placed Oi, which had 41.96 million.