The board of the Onassis Foundation has approved a change to one of its statutes in a move that could mean that the sole descendant of legendary Greek tycoon Aristotle Onassis, Athina Roussel Onassis, may never head her grandfather’s foundation. Its statute prescribed that the president must be at least 21 yearsold and a descendant of Aristotle Onassis, but that has now been changed, said newly appointed chairman Antonios S. Papadimitriou yesterday. Nowhere in the will of Aristotle Onassis does it say that Athina is to take over the presidency and, so far, she has expressed no desire to become a member of the board, added Papadimitriou. Athina turns 21 in January next year. Papadimitriou was unanimously elected to replace his father Stylianos A. Papadimitriou as chairman. Foundation vice presidents Ioannis P. Ioannidis and Georgios A. Zampelas also took over the post from their fathers. The outgoing president and two vice presidents will be life members of the foundation as dictated by the Onassis will.