The ratings agency said there is scope for an upward revision and cited political opposition to policy adjustments and additional external shocks as risk factors.
Advent International has agreed to acquire 80% of Walmart's Brazilian operation.
Tigo is the leading provider with US$13.5mn in mobile banking transactions, followed by Personal, Claro and Zimple.
While the program was received positively, spending cuts in infrastructure, a strengthening dollar and heightened financial risk cast doubt on the plan's financial viability.
When drafting rules to tackle cyber crime, authorities could build on the experience they gained from drafting anti-money laundering regulations.