The bullion miner said independent non-executive director Maria Ramos, who has been an AngloGold director since May 2019, would replace him.

Shares in AngloGold were down 2.64% by 1225 GMT, falling further than other bullion shares listed on the Johannesburg Stock Exchange, which were 0.69% lower.

Ramos is a former chief executive of one of Africa`s largest banks, Absa Group. Prior to that, she was CEO of state-owned freight transport and logistics service provider Transnet.

Pityana`s resignation follows that of former CEO Kelvin Dushnisky, who stepped down in September after just two years in the role, citing family reasons.

Chief Financial Officer Christine Ramon has been appointed interim CEO while the board searches for a permanent replacement.

" having been a member of the board since May 2019, and messaging suggesting no change to strategy should help to allay concerns with this being the second unexpected leadership change at AngloGold in the past 6 months," RBC’s analyst Tyler Broda said in a note.

The company said that, since Pityana, first appointed to the board in 2007, became chairman in 2014, its debt had been cut by more than 70%, the portfolio had been simplified and it had rehabilitated and begun production at the Obuasi gold mine in Ghana.

AngloGold Ashanti, which also has operations in Argentina, Australia, Colombia, Guinea, Mali and Tanzania, announced in February it was selling its South African assets to rival Harmony Gold as part of its plan to shrink its portfolio and focus on assets with higher returns.