This excerpt taken from the C 8-K filed Jan 15, 2008.
Redemption of Depositary Shares
If Citigroup redeems the Convertible Preferred Stock, in whole or in part, as described above under Description of the Convertible Preferred StockRedemption, depositary shares also will be redeemed with the proceeds received by the depositary from the redemption of the Convertible Preferred Stock held by the depositary. The redemption price per depositary share will be 1/1,000th of the redemption price per share payable with respect to the Convertible Preferred Stock.
If Citigroup redeems shares of the Convertible Preferred Stock held by the depositary, the depositary will redeem, as of the same redemption date, the number of depositary shares representing those shares of the Convertible Preferred Stock so redeemed. If Citigroup redeems less than all of the outstanding depositary shares, the depositary will select pro rata, or in any other manner determined by the depositary to be fair and equitable, those depositary shares to be redeemed. The depositary will mail notice of redemption to record holders of the depositary receipts not less than 30 and not more than 60 days prior to the date fixed for redemption of the Convertible Preferred Stock and the related depositary shares.