Benatia had announced on Sunday that he had resigned from OM following the departure of coach Roberto de Zerbi.
However, that gesture has been rejected by McCourt, who instead is restructuring their management team.
Marseille announced in a statement this morning:
"Determined to ensure the best interests of Olympique de Marseille and to achieve the sporting objectives for the current season, Frank McCourt has asked Medhi Benatia to remain in his position until the end of the season.
"Aware of his responsibilities to the club, Medhi Benatia has agreed to extend his notice period until June and will oversee all sporting activities.
"Pablo Longoria’s role is expected to evolve towards his institutional responsibilities, in order to maintain Olympique de Marseille’s representation within French and, in particular, European governing bodies."
As the statement confirmed, Benatia and Longoria have now split their duties, with the former in charge of the football department and Longoria running off-the-field club matters.