The emerging markets specialist is interested in snapping up the 54 per cent stake in the bank owned by Old Mutual.
The bank, which would represent a crucial foothold in Africa’s biggest economy, would cost it more than $5bn (£3.4bn).
Standard Chartered has been linked several times in the past to a possible deal for Nedbank, and chief executive Peter Sands has said he wanted a bigger presence in South Africa.
Analysts say Old Mutual would be receptive to a deal as it has already been urged by investors to review its sprawling structure.
A deal would see Standard Chartered return in force to South Africa after quitting the country in 1987 during the apartheid era.
However, government rules stating Nedbank needs to keep minority black ownership could prove a stumbling block.
Analysts also say South African regulators are keen to protect the financial industry from further foreign encroachment.
Sands has steered Standard Chartered, based in London but deriving over four fifths of its profit from Asia, through the financial crisis relatively unscathed, underpinned by its reliance on Asia and traditionally decent capital.
But even from this base it may be forced to raise extra capital.
Goldman Sachs is rumoured to be advising on the deal.
Standard Chartered, Old Mutual, Nedbank and Goldman all declined to comment on the speculation.