Germany's Commerzbank is acquiring the 21.32% stake in online broker Comdirect Bank currently held by Deutsche Telekom subsidiary T-Online.
The move increases Commerzbank's majority stake on the German online broker from 58.56% to 79.88%.
A Commerzbank spokesman told reporters the shares will be acquired at "close to market price" - which would be around EUR206 million based on Comdirect's closing price of EUR6.86 yesterday.
The transaction is expected to close within the next two days.
According to reports, Commerzbank does not plan to integrate Comdirect into its business and the broker will continue as an independent company under its own brand name.