Deutsche Telekom has faced pressure from rivals

The euro's strength against the dollar is also expected to eat into earnings at the firm whose businesses also include T-mobile UK and T-Mobile USA.

The firm said it expected profits of 19bn euros ($24.5bn; �12.5bn).

It had earlier estimated it would earn between 19.7bn euros and 20.2bn euros in the year.

The change was the result of "extremely tough domestic competitive environment" as well as the developments in foreign exchange rates, the company said in a statement.