Utilize the input text as a context reference, choose the right relationship between Banamex and Citigroup from the options. Options: product/material produced, manufacturer, distributed by, industry, position held, original broadcaster, owned by, founded by, distribution format, headquarters location, stock exchange, currency, parent organization, chief executive officer, director/manager, owner of, operator, member of, employer, chairperson, platform, subsidiary, legal form, publisher, developer, brand, business division, location of formation, creator.

Citigroup Inc. on Wednesday confirmed that it will close Banamex USA, a small unit doing business across the U.S.-Mexico border, and agreed to pay $140 million to regulators who said the unit hadn’t done enough to protect itself from money launderers.

Answer: operator