The troubled French IT services firm held a governance meeting in Paris on Thursday, and during the meeting the board realised it was about to lose on the resolutions.
This came after the representative of the employee shareholder trust switched sides to two rebel investment funds.
Philippe Germond, Atos chief executive, declared the meeting null and void after the employee shareholder trust spokesman - holding 3% of the company - said he planned to vote against the management in favour of the Centaurus and Pardus investment funds, the FT has said.
The two funds oppose Atos' business recovery strategy adopted by the board last year, and want five new directors on the Atos board in a bid to force disposals by the company.
Amid scenes of uproar, Germond accused the employee trust representative of contravening his mandate from the trust. He was then joined on the stage by the firm's finance director and a fellow employee trust member who backed the accusation.
Germond suspended the meeting and then came back to announce that the meeting would be reconvened to a later date, after the shareholder trust had reconvened and confirmed its mandate on all resolutions, he said.