Staley said he doesn't believe Diamond has the "financial capability" to buy the entire unit. Diamond resigned in 2012 amid public and government pressure after the bank was fined 290 million pounds ($411 million) for rigging Libor interest rates. He's now building a banking franchise in sub-Saharan Africa through Atlas Mara and owns eight banks in seven countries. The British firm bought South African bank Absa in 2005 and three years ago the Johannesburg-based unit acquired its parent's operations in eight African nations, giving Barclays a presence in 12 countries on the continent with 12 million customers. 'Won't Rest' Staley rebuffed calls from analysts and investors to exit or spin off Barclays's under-performing investment bank, seen as the main culprit for the two-year slide in shares, calling such demands "shortsighted" earlier this month.