If the sum of the authorised capital of commercial banks owned and controlled by investors from OECD countries, measured as a percentage of the aggregate net capital of all  commercial  banks  in  Mexico,  reaches  25  per  cent, Mexico may request consultations with the OECD Member countries on the potential adverse effects arising from the presence of commercial banks of the other OECD Member countries in the Mexican market and the possible need for remedial  action,  including  further  temporary  limitations on  market  participation.  The  consultation  shall  be completed  expeditiously.  In  considering  the  potential adverse effects, the shall take into account:
1.  the threat that the Mexican payments system may be controlled by non-Mexican persons;
2.  the effects that foreign commercial banks established in Mexico  may  have  on  Mexico’s  ability  to  conduct monetary and exchange rate policy effectively; and
3.  the  adequacy  of  the  provisions  of  the  Codes  with respect to financial services in protecting the Mexican payments system.
"MEXICO
A. Exceptions at national level
I. Investment by established foreign-controlled enterprises […]
Financial institutions: investment in financial institutions as follows […]
f) If the sum of the authorised capital of commercial banks owned and controlled by investors from OECD countries, measured as a percentage of the aggregate net capital of all commercial banks in Mexico, reaches 25 per cent, Mexico may request consultations with the OECD Member countries on the potential adverse effects arising from the presence of commercial banks of the other OECD Member countries in the Mexican market and the possible need for remedial action, including further temporary limitations on market participation. The consultation shall be completed expeditiously. In considering the potential adverse effects, the OECD Member countries shall take into account:
1) the threat that the Mexican payments system may be controlled by non-Mexican persons;
2) the effects foreign commercial banks established in Mexico may have on Mexico’s ability to conduct monetary and exchange rate policy effectively; and
3) the adequacy of the provisions of the Codes with respect to financial services in protecting the Mexican payments system.[...]" (OECD (2017), National Treatment for Foreign-Controlled Enterprises: Including Adhering Country Exceptions to National Treatment, Paris)
OECD (2017), National Treatment for Foreign-Controlled Enterprises: Including Adhering Country Exceptions to National Treatment, Paris
[<a href="https://www.oecd.org/daf/inv/investment-policy/national-treatment-instrument-english.pdf">NTI</a>]