Publicist Karen Sundell says Dileo died Monday.
Before he signed on with Jackson, Dileo was credited with taking Epic Records from a small company to the No. 2 label in the country.
In 1984, Jackson asked him to manage his career, including his Bad World Tour, the largest grossing tour of all time.
They parted in 1989, but Dileo returned to support him in 2005 at his child molestation trial. He was present for Jackson's acquittal and took over as his manager before Jackson died.
Dileo is survived by his wife, Linda.