Carson Yeung has cut all ties with the holding company that owns Championship side Birmingham.
A statement to the Hong Kong Stock Exchange on Tuesday confirmed Yeung has resigned from his position as executive director with Birmingham International Holdings Limited (BIHL).
The BIHL statement read: "The board of directors of Birmingham International Holdings Limited announces that Mr Yeung Ka Sing, Carson ("Mr Yeung") has resigned from all directorships of the group, including his position as an executive director with effect from 4 February 2014.
"Mr Yeung resigned for the reason to devote more time to his other personal commitments. Following his resignation, Mr Yeung holds no positions in the group."
Yeung, who is awaiting the verdict in a trial for money laundering in Hong Kong, which he denies, completed a takeover of Birmingham through BIHL in 2009. Since he took charge, Birmingham have won the League Cup but have been relegated from the Premier League.
Yeung's position as chairman of BIHL has been taken by fellow executive director Cheung Shing.
It is understood that Yeung remains president of the football club.