Birmingham co-owners David Sullivan and the Gold brothers, chairman David and Ralph, have increased their stake in the midlands club.
It means that between them the long-serving trio now own almost 50% of City's shares.
Sullivan splashed out £574,000 to increase his stake to 24.45% and the Golds between them have spent an additional £895,000 to increase their holding to 25.06%.
David Gold has also individually purchased an additional number of shares for £43,696.
It is another blow to the club's largest individual shareholder Carson Yeung who has attempted to have ex-Liverpool star Steve McManaman and former Crystal Palace player Fan Zhiyi voted onto the board as his representatives.
Yeung was hoping the duo would be voted on at an EGM but the club's managing director Karren Brady recommended shareholders vote against the move in a letter.
McManaman is a UK advisor for Hong Kong-based businessman Yeung who bought a 29.9% stake in Birmingham last summer.
But Yeung angered Sullivan and David Gold when his pledges to complete a takeover of the club fell through in December.
Yeung's spokesman Sammy Yu said: 'With holding a 29.9% stake, we really hope to get more involved for the good of the club and the benefit of everyone.'
But Sullivan and David Gold are determined that Yeung will have no extra involvement and will continue to block any moves he makes in that direction.
The debacle over his collapsed takeover bid left them angry and frustrated and also contributed to the departure of the then manager Steve Bruce.
Ironically, McManaman has today distanced himself from becoming a Blues board member.
Meanwhile, Brady has sold her shareholding in City for £262,875.