"Our main request is that the chairman steps down and that the board members which have been there the longest are replaced with new members who are well recognised in the IT industry", Cyril Charlot, founding partner at Paris-based Sycomore Asset Management, told Reuters.

Sycomore Asset Management owns between 0.5% and 1 % of Atos. Atos did not have an immediate comment on Sycomore's call for Chairman Bertrand Meunier to resign.

(Reporting by Julien Ponthus and Mathieu Rosemain, editing by Silvia Aloisi)