Merckle, a respected businessmen with a wife and four children, jumped in front of a train in the town of Blaubeuren in southwestern Germany, officials said Tuesday.
His business empire had run into trouble in the crisis, and its problems were compounded by heavy losses in trading of shares in automaker Volkswagen AG. Merckle's business interests included generic drug maker Ratiopharm International GmbH and cement maker HeidelbergCement AG.
Merckle's family said in a statement that "the distress to his firms caused by the financial crisis and the related uncertainties of recent weeks, along with the helplessness of no longer being able to act, broke the passionate family businessman."
Authorities said he left a suicide note, but gave no details. Merckle's death appears to be at least the third comparable suicide in less than four months.