By Tatiana Bautzer NEW YORK (Reuters) -Citigroup has agreed to sell a 25% stake in Grupo Financiero Banamex to a company owned by Mexican billionaire Fernando Chico Pardo and his family, marking a step toward Citi's plan to take the unit public. The sale, worth 42 billion Mexican pesos ($2.28 billion), is expected to close in the second half of 2026, the bank said in a filing. The deal values Banamex at $9.12 billion at the current foreign exchange rate. Citigroup bought Banamex in a $12.5 billion deal ...