The American banker – often criticised for the size of his pay cheques – has become a non-executive director of a cash shell which has ambitious plans to buy into fast-growing African banks.
The 62-year old, who was forced out of Barclays after regulators said they had lost confidence in his management, has linked up with Ashish Thakkar, who started his first IT company in 1996 at the age of 15 in Uganda and now runs a conglomerate with operations in 19 African countries.
The listed company – known as Atlas Mara Co-Nvest – is based on Diamond's New York company Atlas Merchant Capital and Thakkar's Mara range of businesses across Africa. The two companies have invested $20m.
Diamond's interest in Africa is well known. Through his family charity – the Diamond Family Foundation – he has been attempting to set up an annual lecture on Africa and is known to have visited Nigeria recently.
In a stock market announcement Atlas Mara Co-Nvest said it did not have any discussions with target companies under way and said it could make acquisitions anywhere in the world.
"However, given the experience of the company's founders and its board, the company expects to focus on acquiring a company or business in the financial services sector with all or a substantial portion of its operations in Africa," the announcement said.
"The directors believe that there are significant gaps in the market today including the need for capital created by European financial institutions retreating to their home territories due to the sovereign debt crisis and the Basel III regulatory framework at a critical time for growth in Africa."
The former boss of Africa's Ecobank, Arnold Ekpe, has been appointed chairman of the company, which has also named a number of non-executive directors, including Rachel Robbins, a former vice president of the International Finance Corporation.
Diamond left Barclays in July 2012 just days after the bank was fined for rigging Libor and after the bank's then chairman, Marcus Agius, was summoned to the Bank of England to be told that Diamond needed to leave.
Agius, who also quit, told MPs on the Treasury select committee how he had been summoned to see the then Bank of England governor, Lord King, with the bank's non-executive director, Sir Michael Rake.
"We had a conversation in which he said that Bob Diamond no longer enjoyed the support of his regulators," said Agius at the time.