To fund the enhanced supervision of banks mandated of it by the Dodd-Frank Act, the Federal Reserve Board of Governors is proposing a new fee for big banks that is intended to raise as much as $440 million.

A proposal published on Thursday in the Federal Register seeks comments on a plan to establish an annual assessment of bank holding companies and savings and loan holding companies with $50 billion or greater in total consolidated assets. The fee would also be required on nonbank financial companies designated by the Financial Stability Oversight Council for supervision by the Federal Reserve.

The Dodd-Frank Act directed the Federal Reserve to impose assessments and fees equal to the funding required to carry out its expanded supervisory and regulatory responsibilities for these large financial companies. The proposed rule outlines how it would determine which companies are assessed, estimate the total expenses necessary, and determine the formula for calculating each company's assessment.

Under the proposal, 2012 would be the first assessment period, although payments would not be collected until the rule is finalized. The Federal Reserve estimates that for 2012 there would be approximately 70 assessed companies with aggregate total assessable assets of approximately $20 trillion. Using these figures, a company with total assessable assets of $50 billion would be required to pay an assessment of approximately $1 million and a company with total assessable assets of $1 trillion would be required to pay an assessment of approximately $22 million.

Under the plan, each calendar year would be an assessment period and the Federal Reserve would notify each institution of its assessment no later than July 15 of the year following the assessment period. Payments would be due by Sept. 30 and companies would pay using the Fedwire Funds Service to the Federal Reserve Bank of Richmond, with payments later transferred to the U.S. Treasury's General Account. Late payments will be assessed a daily interest charge.

Comments on the proposed rule must be submitted by June 15.