* US financial giant Citigroup has announced that it has halted talks to sell its controlling stake in Mexico’s Banamex retail bank, one of the country’s largest retail banks, and instead will sell its shares in an initial public offering (IPO). The main prospective buyer had been Grupo México, a rail freight-to-mining conglomerate owned by Germán Larrea, one of the country’s wealthiest business leaders. Citigroup’s announcement came the day after President Andrés Manuel López Obrador said that the government would consider buying a controlling stake in Banamex and follows a decree issued last week by López Obrador expropriating part of the Ferrosur rail network operated by Grupo México.