Old Mutual PLC, the Anglo-South African financial-services firm, is plotting a 9 billion pound ($12.8 billion) breakup that could trigger a takeover battle for its various operations, Sky News reported.

Without citing sources, it said the group is working on a plan to divide itself into stand-alone companies based on its stake in the South African lender Nedbank Group Ltd., its U.K.-focused wealth unit, its emerging-markets operation based in South Africa and its institutional asset management business.

Sky News reported two private-equity firms, Cinven and Warburg Pincus LLC, are already said to have tabled a multibillion pound joint cash offer for Old Mutual Wealth.

A representative of Old Mutual declined to comment, as did representatives of Cinven and Warburg Pincus.

Old Mutual is due to publish full-year results March 11.

Its shares have fallen 21 percent over the past year, with the group hurt by a weak rand. They closed Friday at 178.6 pence, valuing the business at 8.83 billion pounds.