Mexico City, Mexico – According to Mexico's Financial Stability Council, or CEF, foreign financial institutions operating in the country will be prohibited from transferring capital out of their Mexican units to address problems in their home countries.

The CEF, which is made up of representatives from the Finance Secretariat, the Bank of Mexico, and other agencies, said recently issued rules limited the operations of multi-branch entities with "persons with relevant links."

"These rules complement the measures taken by Mexican authorities to safeguard the financial system from the situation in countries where banks operating in Mexico are headquartered," the CEF said in a statement.

The rules, which went into effect on October 11th, require prior authorization from the Bank of Mexico for executing "significant transfers of assets and other operations between the bank and its related parts," the CEF said.

The 22 financial groups operating in Mexico had total assets of about $457.32 billion as of June 30, 2012.

The largest banks operating in Mexico, by assets, are BBVA Bancomer, a unit of Spain’s BBVA; Banamex, a subsidiary of US-based Citigroup; Santander Mexicano, a unit of Spain’s Santander; Banorte, which is controlled by Mexican interests; and HSBC de Mexico, a unit of London-based HSBC Holdings plc.