Arsenal majority shareholder Stan Kroenke says his shares "are not, and have never been, for sale".
The American's company released a statement on Monday following the recent £1bn bid by Alisher Usmanov to take full control of the Gunners.
Kroenke Sports and Entertainment added it was "a committed, long-term investor in Arsenal and will remain so".
The statement comes a day after Arsenal failed to qualify for the Champions League for the first time in 20 years.
Usmanov owns 30% of shares in the club but is not part of the board or decision-making at the club.