Birmingham have reached an agreement to sign Charlton defender Michael Morrison on a permanent transfer.
The 26-year-old has impressed Blues boss Gary Rowett since joining on-loan from Charlton in October, starting the last six games.
He will now sign a three-and-a-half-year contract in the January transfer window once the temporary deal expires on December 31.
Morrison played a key role in the Addicks' record-breaking League One title season in 2011/12 and was named vice-captain the following campaign.
However he made just three appearances for the Addicks since August before making the temporary switch to St Andrew's in order to play first-team football.