The company aims to raise between 1.5 billion reais and 2 billion reais (£317 million-£427 million) from the divestitures, the sources added, asking for anonymity because they cannot discuss the plans publicly.
Oi and Bank of America had no immediate comment on the matter.
Preferred shares in Oi, flat before the Reuters report, rose 1.4 percent to 1.46 reais. The benchmark Bovespa index was down 0.25 percent.
Oi filed for bankruptcy 2-1/2 years ago to restructure 65 billion reais in debt.
Before filing for what was Latin America's largest ever bankruptcy proceeding, Oi had raised around 3 billion reais by selling more than 3,600 cellular towers to the Brazilian unit of SBA Communications Corp in transactions closed in 2013 and 2014.
The company plans to make investments aimed at improving its mobile and broadband operations and boosting its market share at the same time as it pursues the asset sales.
The distressed asset managers that are Oi's top shareholders plan to focus on improving the company's mobile and broadband operations rather than a near-term sale of their stakes, Reuters reported last year.
Investment firms Solus Alternative Asset Management LP, GoldenTree Asset Management LP and York Capital Management Global Advisors LLC last year became Oi's largest shareholders after converting their debt in the company into equity stakes as part of its restructuring.
Oi has forecast capital expenditures of 7 billion reais a year over the next three years.
(Reporting by Tatiana Bautzer; editing by Christian Plumb, Jonathan Oatis and Rosalba O'Brien)
By Tatiana Bautzer