JOHANNESBURG, July 23 (Reuters) - South Africa's Deputy Finance Minister David Masondo has resigned as the chair of the board of directors of state-owned asset manager the Public Investment Corporation, he said on Thursday.

The asset manager faces mounting scrutiny after its chief executive was suspended pending an investigation into allegations raised by a whistleblower. South Africa's financial regulator has also launched a governance probe.

"After careful reflection, I have decided to resign as Chairperson of the Board of the Public Investment Corporation," Masondo said in a statement.

The asset manager is one of Africa's largest, overseeing more than 3 trillion rand ($178.31 billion) of funds.

Its biggest client is South Africa's Government Employees Pension Fund, and it is the largest investor on the Johannesburg Stock Exchange.

The PIC has faced governance challenges for more than a decade, and many of the issues now confronting the institution echo findings of a judicial inquiry, which in 2020 identified weaknesses in oversight, accountability and investment decision-making.

($1 = 16.8245 rand)