More than one hundred employees from Postbank, a unit of Deutsche Bank, demonstrated outside the headquarters of Germany's biggest lender on Friday over concerns the subsidiary may be sold off.

The giant services sector union Verdi had organised the rally in front of the twin-tower skyscraper in Frankfurt's financial district.

The protestors were "very concerned" about different rumours and newspaper reports suggesting that Postbank -- which Deutsche Bank acquired a few years ago -- might be sold, said a member of the unit's works committee and Verdi representative, Gerd Tausendfreund.

"The atmosphere within Postbank isn't good. We want job guarantees until 2020," he told AFP.

Deutsche Bank is scheduled to unveil a new corporate strategy soon as it struggles to confront the challenges of increased financial sector regulation and the low interest rate environment.

The group's supervisory board was scheduled to meet Friday, and the new strategy could be announced as early as next week when it publishes its first-quarter results.

Postbank, a former state-owned unit of the German postal group, has around 14 million customers and posted a net profit of 278 million euros ($302 million) last year. It is headquartered in the western city of Bonn and has a workforce or around 9,800.