The union called for debate on Forgeard's so-called "golden shake" which has already come under heavy fire in France.
"We are critical of these managers who fail, but who nevertheless receive payments that are provided for in their contracts," a spokesman for IG Metall's north German branch, Daniel Friedrich, told AFP.
"Urgent debate is required on the matter. The payments must be cancelled if the managers fail."
In addition, the general principle of high salaries for executives was "untenable" for the union, Friedrich said.
"Employees don't understand why their wages are continually cut, while managers' pay continuallly rise, ostensibly in the name of remaining competitive at a global level," the spokesman said.
Bumper pay-off for ex-CEO
