The bank is considering two options, both of which involve the sale of Postbank, according to the Financial Times' source: to sell shares in Postbank while also cutting assets at its investment bank by €160 billion (US$172 billion); or to split the whole bank in two and eventually sell off all retail businesses as one merged legal entity.
Deutsche Bank would then retain its investment banking, asset and wealth management and global transaction banking divisions, the Financial Times source said.
Deutsche Bank's rate trading business and brokerage operations would be the more likely candidates for sale under the first option, the report said, as they have been affected by new capital rules.
Postbank workers have gone on strike demanding employment protection, in reaction to the potential sale, City AM said.
Deutsche Bank told the Financial Times that: "Strategy 2015+, our three-year plan launched in 2012 comes to its natural conclusion this year. We have been transparent that the bank is reviewing and updating its strategy, and that we will communicate further in the second quarter after decisions are made."
A German government spokesperson told Reuters that the decision "is a purely corporate decision of Deutsche Bank".
Headquartered in Bonn, Postbank has 1,100 of its own branches as well as 4,500 Deutsche Post "partner branches", according to its own website. It has 14 million clients, 14,800 employees, and assets amounting to €155 billion.
Deutsche Bank first acquired a stake in Postbank in 2008, and has gradually bought more of the company, according to the Postbank site. It now owns 93.7% of the company.