The Basel Committee brings together regulators from around 30 countries to coordinate rules for their banks. Its members include the Bank of England, US Federal Reserve, European Central Bank and the China Banking Regulatory Commission.
In a letter seen by the Financial Times, the European Banking Federation, the Japanese Bankers Association and the Canadian Bankers Association say that the proposed rules would "significantly increase capital requirements" and in turn reduce their ability to lend money.
The banking associations are concerned about plans to limit how far a bank can use internal risk models to decrease its capital requirements.
"The successful completion of the regulatory reform requires, more than ever before, striking a balance between financial stability and economic growth, especially in jurisdictions whose economies are highly dependent on bank lending," the associations wrote, according to the Financial Times.
Banking reform expert Tony Anderson of Pinsent Masons, the law firm behind Out-Law.com said that the Basel Committee will listen to what the banking associations have to say, but "it is difficult to see it acting upon the letter without further input and consideration from other bank associations and further analysis of a wider range of issues including the relative size of banks within domestic markets"
The Basel Committee issued revised minimum capital requirements in January. Under these, global banks will need to increase the amount of capital held against their trading books by the start of 2019, but by less than had been expected.