The Bundesbank said it had acted solely to fight domestic inflation and not out of international rate concerns.
Thus, returns from United States corporations are eroded by domestic inflation.
And with domestic inflation low, American businesses find it difficult to pass along the extra cost to their customers.
An increase had generally been expected soon because the bank is intent on fighting domestic inflation regardless of the economic pain it causes its allies.
Historically, the major objective of monetary policy had been to manage or curb domestic inflation.
But by making imports less expensive, a higher dollar also helps keep domestic inflation under control.
The sharp fall in the dollar this week exacerbated worries of higher domestic inflation ahead.
But the latter charge concerning domestic inflation appeared to be correct.
This depreciation should tend to offset the effects of the domestic inflation.
The strong euro and high domestic inflation are making the country a less competitive place to do business, the bank said.