Co-founder and largest shareholder Elaine Wynn who has been in a proxy fight with the board, has been asking shareholders to vote against Hagenbuch's re-election, whom she called a close friend of the company founder and former Chief Executive Officer Steve Wynn.

Steve, Elaine's ex-husband, resigned earlier this year on allegations of sexual misconduct and disposed his entire 11.8 percent stake in the firm for $2.1 billion.

In a letter, Elaine said "Mr. Hagenbuch represents all that is wrong with the long-serving legacy directors," suggesting a revamp of the board, given the proximity of board members to Steve.

In April new Chief Executive Officer Matt Maddox detailed steps the company had taken to distance itself from its founder and adjust its corporate culture, including adding three women to its board.

The company also said on Monday Robert Miller has resigned from the board.

The company's shares were down 2 percent at $191.70 in after-market trading.

(Reporting by Taenaz Shakir in Bengaluru; Editing by Shounak Dasgupta)