DWS told Financial Times Deutschland that it is increasingly concerned with investments from outside Germany, which may cause the loss of its leadership at home.
DWS' managing director, Klaus Kaldemorgen, told the newspaper that DekaBank, the investment fund manager of Germany's state-owned savings banks, has an "enviable'' distribution network through its savings banks.
Currently, DWS has a 22 per cent market share in Germany, while DekaBank owns 20 per cent of the market.
By November, DWS had attracted $21.5 billion of investment for the year, $13.6 billion of which came from Germany and the rest from abroad, the newspaper said.
Meanwhile DekaBank took $17.5 billion from January to September in German investment.
DekaBank's chief Franz Waas has already said the bank aims to leapfrog DWS in the German market by 2009.