But the coming legislation is too focused on the United States to be a reasonable option for global banks, said Mayra Rodriguez Valladares, the managing principal of consulting firm MRV Associates.

Banks operating in a global environment have to contend with capital regulations in all of the countries in which they operate. Most of those countries, including the U.K., Canada, China, Japan, Russia and members of the European Union, are members of the 27-country Basel Committee on Banking Supervision.

Those countries have either put in place the requirements demanded by the 2010 Basel agreement or are in the process of doing so.

Should the U.S. veer off that standard, banks will be faced with the huge costs and complications of maintaining multiple compliance systems, Rodriguez said.

“That actually causes a real technological and systems nightmare for banks,” she said.