The comments assume significance given the protracted stand-off in the past between him and the previous Infosys management over issues of corporate governance and severance package doled out to former executives like Rajiv Bansal.
Stating that he had worked with 'Ranga' for over 15 years, Murthy said he has been "instrumental" in raising investor confidence in the company during the last five years by managing costs and margins.
"His ability to take tough decisions in challenging situations, his solid financial expertise, strong value system, unfailing courtesy and flawless execution always distinguished him as an exemplary leader and a key asset for the company," Murthy added.
Earlier on Saturday, Infosys said Ranganath has resigned after an 18-year stint at India's second largest IT services firm.
He took over as CFO in 2015 after the exit of Rajiv Bansal.
Ranganath will continue in his current position as CFO till November 16, 2018, Infosys said in a statement.