Citigroup Inc. (C) is planning to sell its shares in Brazilian credit card networking services provider Redecard SA (RDCD3.BR) through a secondary offer on the Brazilian Stock Exchange, or Bovespa, Redecard said in a statement late Wednesday.

The shares will be sold in Brazil and also to foreign investors in the form of Global Depositary Receipts, or GDRs.

The company didn't give the exact amount of shares to be offered by Citigroup nor a timetable for the operation, which still must be approved by Brazilian Securities Commission, or CVM.

Citigroup could raise around 2.94 billion Brazilian reals ($1.23 billion) based on Redecard's closing price Wednesday of BRL25.66 on the Bovespa.

Redecard is jointly controlled by Brazilian banking giant Itau-Unibanco and Citigroup. Currently, Itau-Unibanco has a combined 46.42% stake in Redecard, while Citigroup has a 17% stake.

Itau-Unibanco was formed late last year by the merger of Itau (ITU), at that time Brazil's third-largest bank, and Unibanco (UBB), at that time the country's fourth-largest bank.

On Wednesday, the president of Itau-Unibanco, Roberto Setubal, said that the bank isn't interested in buying a Citigroup (C) stake in Redecard.

"We are already the holder of a controlling stake in Redecard," Setubal said at a news conference. "We are not interested in making Redecard into a subsidiary of the bank. We prefer to have other banks as our partners in Redecard. Redecard was designed to have a number of banks as partners."

-By Rogerio Jelmayer, Dow Jones Newswires; 5511-2847-4521; rogerio.jelmayer@dowjones.com