Echo Entertainment chairman John Story says he will fight attempts by billionaire James Packer to kick him out of his job.
Mr Packer has called on Echo to hold a special meeting of shareholders within weeks so they can vote on his proposal to dismiss Mr Story immediately and install former Victorian premier Jeff Kennett on the board.
But Mr Story says he has the full support of Echo's directors.
Asked by Sydney's Daily Telegraph newspaper if he would step aside, he replied: "Of course, I'm not".
Mr Packer owns rival casino company Crown, which is Echo's biggest shareholder.
Crown holds a 10 per cent stake in Echo, which owns Sydney's only casino The Star.
Analysts say Mr Packer's move to oust Mr Story is aimed at helping the billionaire gain a foothold in the lucrative Sydney market.