This comes after International Adviser reported that the firm had suspended Moyo on 24 May.
Chief operating officer Iain Williamson will continue to act as chief executive for Old Mutual until further notice while it looks for a new boss through its usual recruitment channels.
The firm has said that Moyo’s dismissal was linked to concerns over his relationship with an investment holding company he co-founded called NMT Capital, which he spoke about after the original suspension.
Old Mutual said that, although Moyo had declared the conflict of interest before he was employed by Old Mutual and was governed by “specific protocol” to regulate any related issues, it decided to terminate Moyo’s contract after a report by the Old Mutual Related Party Transaction Committee (RPTC), a committee of independent OML board members.
Old Mutual’s statement said: “During this process, various concerns emerged relating to Moyo’s conduct in relation to his conflicting interest.
“One of the concerns raised involved two declarations of ordinary dividends by NMT Capital during 2018 totalling ZAR115m (£6.3m, $7.8m, €7m).
“The resultant benefit to Mr Moyo and his own personal investment company was ZAR30.6m.
“These dividends were declared in breach of Old Mutual’s rights as a preference shareholder, since arrear preference dividends were unpaid at the time and, at the time of the second dividend declaration, the preference share capital was redeemable.
“The preference share capital remains unpaid. Mr Moyo chaired the board meeting of NMT Capital at which the second ordinary dividend of ZAR105m was declared.”
These issues were investigated and reported to the firm’s Corporate Governance and Nomination Committee (NomCom) in March 2019.
NomCom considered these matters at several meetings during April 2019 and the firm’s board debated the issues at two meetings during May 2019.
The firm said it was not “provided with an acceptable explanation why, in clear contravention of the relevant preference share agreement with Old Mutual as well as Moyo’s employment obligations, ordinary dividends were declared whilst debt to Old Mutual was outstanding”.
This led to the firm to the conclusion that there was a “material breakdown in trust and confidence in Moyo”.
It said that Old Mutual and Moyo could not reach an agreement on an agreed separation, and therefore he was suspended.
Old Mutual also said: “Moyo’s actions since the suspension contravened his fiduciary duties to Old Mutual, his contract of employment and his notice of suspension.
“Following unsuccessful attempts to engage on the terms of separation, the board has now resolved to give notice of termination of employment”.
The sacking of Moyo has no connection to Quilter or Old Mutual International, which has yet to adopt the group’s branding.