Shareholders at Independent News and Media are due to vote today on proposals which would impose restrictions on anyone increasing their stake in the company.
The move comes amid a row between the company's chief executive, Tony O'Reilly, and rival businessman Denis O'Brien.
Mr O'Brien recently increased his stake in INM to 8% and criticised the company's board, which he claimed was packed with O'Reilly's cronies.
The two men have been bitter rivals ever since O'Reilly won the battle to buy Eircom.
The resolution being voted on at an EGM today could see dividends and voting rights withheld from some INM shareholders in certain circumstances.