The deal would end SocGen's nearly three decades in South Africa as it looks to cut costs and focus on its key markets.

South Africa's third-largest lender Absa is the frontrunner to buy SocGen's sole branch in Johannesburg, one source said.

"I've heard that Absa is interested in SocGen's Johannesburg custody services," one source said, declining to be named because the information is confidential.

Custody services include the safe-keeping of shares, bonds and cash for clients.

The likely sale was corroborated by a second source, who said the SocGen's Johannesburg branch was up for sale, adding that it would be affordable for Absa - a 145 billion rand ($11 billion) company with nearly one trillion rand in assets.

SocGen, Absa and the South African Reserve Bank -- which regulates banks and requires them to give notice of such deals -- declined to comment.

Buying SocGen's South African business would hand Absa, formerly Barclays Africa, a company with nearly 9 billion rand (£515.1 million) in assets.

It would also underline CEO Maria Ramos' determination to broaden Absa's product offering under a new strategy to regain market share at home and double the sales contribution from its 10 operations elsewhere in Africa.

The deal would mark Absa's return to custody services after selling its own business in 2013 to align with its former parent Barclays, which has since sold most of its controlling stake in the South African bank to focus on the United States and Britain.

(Reporting by Tiisetso Motsoeneng; editing by James Macharia and Jason Neely)