The U.S. Treasury Department plans to start charging large banks a fee to cover the costs of the financial risk council it leads and a research office tasked with measuring threats to financial markets.

The Financial Stability Oversight Council and the Office of Financial Research were created by the 2010 Dodd-Frank financial oversight law, which instructs the government to bill banks for their operations.

Treasury on Thursday released a proposed rule, which would apply to banks with more than $50 billion in total assets, starting in the middle of next year.

Treasury is proposing charging these banks a flat rate that would be applied to an institution's total consolidated assets, and would be collected twice a year.

The department has yet to announce the specific fee banks will be charged because the budget for the council and research office will not be known until President Barack Obama releases his fiscal 2013 budget proposal early next year.

The research office reports to FSOC, which is charged with monitoring and acting on risks to the financial system.

All major financial regulators, such as the Federal Reserve and the Securities and Exchange Commission, are part of FSOC.

The council was created so that regulators could work more closely together to anticipate problems in markets, like those that led to the 2007-2009 financial crisis.

The research office gathers and analyzes financial market data for the council.

Treasury said it plans to have a final fee rule out no later than the end of May and will let banks know what their tab is in June.

The fees will first be collected in July.

Treasury said the collected fees will be enough to cover six months of OFR and FSOC operating expenses and 12 months of capital expenses.

The proposed rule will be subject to 60 days of public comment.

(Reporting By Dave Clarke; Editing by Tim Dobbyn)