Bradley Abelow, the president and chief operating officer, and Henri Steenkamp, the chief financial officer, both say they don't know where the money is or why it is missing.
Abelow says he cannot explain what happened to the money without access to MF Global documents, which a trustee now controls.
Steenkamp says he had no direct involvement with transfer of funds.
Former Sen. Jon Corzine, who led MF Global as CEO until last month, told a congressional panel last week he doesn't know what happened to the money. All three will testify Tuesday before the Senate Agriculture Committee.