(Recasts with details of his departure and transition, other conference call details, share reaction)
SAO PAULO, Oct 10 (Reuters) - Amos Genish, chief executive of Telefonica Brasil SA, on Monday said the firm will undertake a smooth leadership transition, seeking to allay investor concerns after the rushed news of his departure sent shares sliding.
In a conference call to discuss his decision to leave, Genish said Telefonica Brasil will help new CEO Eduardo Navarro de Carvalho to keep delivering "superior results" through a newly formed strategy committee.
Preferred shares of Telefonica Brasil fell nearly 6 percent in Sao Paulo trading on the news, first reported by Reuters on Sunday. Genish said his departure had been discussed for around three months, but the announcement had to be moved up from Oct. 25 due to leaked news of his departure.
"I am very confident the team will continue to excel and reach new heights," said Genish, who took over last year after Telefonica Brasil bought GVT Holding SA, the broadband operator he founded, from France's Vivendi SA for more than 7 billion euros ($7.8 billion).
"The mix of GVT and Telefonica executives has created a very balanced team," said Genish, who will stay on as CEO through December to oversee the transition. He said the decision to leave was personal and declined to elaborate on career plans.
Telefonica Brasil said on Sunday that Genish would begin working immediately on the transition with Navarro, currently Chief Commercial Digital Officer at Spanish parent company Telefónica SA.
$1 = 0.89 euros Reporting by Ana Mano; Editing by Chizu Nomiyama