Robert Diamond’s Atlas Mara Co-Nvest Ltd. (ATMA) agreed to buy ABC Holdings Ltd. and ADC African Development Corp. for as much as $265 million in the first acquisition by the investment firm of the former Barclays Plc (BARC) head.

BancABC offers financial services in Botswana, Mozambique, Tanzania, Zambia and Zimbabwe, Atlas Mara, which trades in London, said in a statement late yesterday. ADC, which trades in Frankfurt, owns 47.1 percent of BancABC and 9.1 percent of Union Bank of Nigeria, the company said.

“We looked extensively at where the best opportunities would be in Africa and we had our sights on a high-quality, multi-country bank in one of the regions of Africa,” Diamond told reporters today in Gaborone, the capital of Botswana. “We are not passive investors and we want to truly add value.”

Diamond, who quit as Barclays chief executive officer in July 2012 after the British bank was fined for manipulating benchmark interest rates, and Ugandan entrepreneur Ashish Thakkar raised $325 million in an initial public offering for Atlas Mara in December. The investment firm, to which Diamond and Thakkar committed $20 million of their own money, is looking for African financial-services companies that can help businesses manage currency and commodity risks.

Atlas Mara said it agreed to pay 82 cents a share for BancABC and offered 1.25 of its own shares for each one of ADC’s. Investors with 34.1 percent of ADC’s stock have agreed to tender their shares, it said, adding that the acquisition will be funded from the proceeds of the IPO.