Birmingham's directors have agreed to sell 29.9% of the club's shares to Hong Kong businessman Carson Yeung.
David Gold (right) will insist on funds to keep Steve Bruce smiling
David and Ralph Gold as well as David Sullivan have each agreed to sell 14.81% of the club's shares to Yeung.
Karren Brady Brady has agreed to part with a 0.23% stake, with fellow director Roger Bannister completing the agreement, by offering to sell 0.05%.
The arrangement makes Yeung the largest individual shareholder, but does not put him in total control of the club.
Sullivan and the Golds will still maintain a major role, though the door is open for Yeung to gain a controlling interest.
In the new arrangement the stakes of the Gold brothers and Sullivan fall to 23.22% each.
Brady's revised holding will be 0.54% and Bannister will retain 0.11%.
It was originally thought Yeung would splash out about £50m and end Sullivan and the Golds' 14 years in charge at St Andrews.
But Yeung has come to his decision after holding talks with Sullivan and the Golds over the past few days.
The billionaire, who made an unsuccessful bid to take over Reading, has had his representatives visit St Andrews to inspect the club's finances.
Sullivan and the Golds also insisted that transfer funds would be made available to manager Steve Bruce.
Indian steel magnate Lakshmi Mittal had also been linked with a prospective move to buy Blues, who won promotion to the Premiership in April.
Sullivan has made it clear on several occasions that he would be happy to sell his stake in the club after 14 years and it is believed he has become weary of travelling from his Essex base to the Midlands.