The operator has been searching for a way to restructure its Central American businesses since February.
It reached the deal in an effort to cut its debts, and proactively manage its assets by merging with CMI, which already holds a 40% stake in Telefónica’s Movistar brand.
As part of the agreement, CMI will pay the operator an additional $72 million depending on the assets’ performance.
Telefónica said in a statement: “This agreement allows Telefónica to leverage its experience and global footprint with CMI’s know-how and local expertise.
“This new business model offers the opportunity to continue business development in the markets where both companies will work together,” they added.