While DWS will not be able to achieve its goal of 3 to 5 percent net inflows this year, it remains committed to this target in the medium term, the group said in a statement on Wednesday, adding that it continues to expect revenues to decrease in 2018.

"We continued to optimise our cost base during the quarter, putting us on track to achieve 20 to 30 percent of our medium-term gross savings target this year," Chief Financial Officer Claire Peel said.

In the second quarter, DWS saw clients pull 4.9 billion euros in assets, while adjusted pretax profit rose 7 percent to 149 million euros (£132.29 million). Management fee margins slipped 0.3 basis points to 30.7 basis points, but the adjusted cost income ratio improved 90 basis points to 74.1 percent.

Swiss peer UBS on Tuesday also reported 1.2 billion francs in net outflows, saying that was due mainly to U.S. customers liquidating part of their investments to pay taxes.

(Reporting by Arno Schuetze; Editing by Victoria Bryan)