Foreign financial institutions operating in Mexico will be prohibited from transferring capital out of their Mexican units to address problems in their home countries, the Financial Stability Council, or CEF, said.

The CEF, which is made up of representatives from the Finance Secretariat, the Bank of Mexico and other agencies, said rules issued on Oct. 10 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 took effect the day after they were published, 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 5.99 trillion pesos (about $457.32 billion) as of June 30.

The largest banks operating in Mexico, by assets, are BBVA Bancomer, a unit of Spain's BBVA; Banamex, a subsidiary of U.S.-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. EFE