The bank's commercial unit has roughly 5 billion reais ($1.34 billion) in assets, out of 75 billion reais for Citi's Brazilian operation as a whole, most of it dedicated to larger corporations.

Rubens said those assets jumped by 27 percent in 2018, as an economic recovery increased demand. Deposits grew 10 percent to 3 billion reais.

Citi is targeting firms with between 200 million and 1.8 billion reais in revenues, he said.

This move underscores a shift in Citi's strategy in Brazil toward wholesale activities after selling its retail assets there to Itaú Unibanco Holding SA for 710 million reais.