A Dutch court convicted Frans van Anraat of war crimes in 2005. He is serving a 16 1/2 -year prison sentence.
Judges ruled that he was Iraq's sole supplier of a chemical called TDG, or thiodiglycol, used to make mustard gas that was later unleashed in a deadly attack on Kurdish rebels.
Prosecutors said in a statement Wednesday the latest request is an appeal after judges earlier ordered a smaller amount confiscated.
It is unclear whether they will recover the profits. Van Anraat claims he spent his money fleeing from country to country after Saddam's regime fell.