Big banks are considering filing lawsuits against the new deposit insurance fund requirements from the Federal Deposit Insurance Corp. Under the new rule, larger financial institutions are required to pay more into the fund, which is used to insure all of America's banks. On Monday, the FDIC announced the finalized rule that changed the way banks are charged. Those deemed to be utilizing risk as a strategy to a great extent will be charged accordingly. It proposed the new rules in November 2010 to eliminate its reliance on debt issuer ratings and make their assessment more forward looking. Beginning April 1, the FDIC will base its assessment on what the banks hold in assets minus tangible equity, instead of what they hold in deposits. This means larger banks will be charged more, and they are considering litigation against the FDIC over the rule, according to analysts. The proposed rule in November offered a 25 basis point levy against brokered deposits, which are sold by the bank to brokers who divide them into smaller pieces for sale to customers. Joseph Mason, professor of finance at Louisiana State University filed a comment with the FDIC saying the proposal would increase the cost of brokered funding by 25% or more in today's rate environment. "Unfortunately, that increase is occurring at a crucial time in the economic recovery when banks are in dire need of funding to make investments in firms and industries that can create the economic value that is the basis for growth," Mason said. The FDIC responded to similar comments by reducing the levy from 25 bps to 10 bps, quelling those opposed to this part of the rule. Other complaints remain. When the FDIC announced the new rule was finalized, the oldest banking association in the country, the Clearing House Association issued a statement saying that the rule violated the Federal Deposit Insurance Act, specifically a section that states a "risk-based assessment system" be calculated  on the probability that the DIF will incur a loss with a specific institution. "It is important to note that the statute refers only to losses that the DIF may incur – there is no reference to losses that other elements of the Federal government, such as the Treasury or the Federal Reserve, may incur in preventing or dealing with a bank failure," said Bert Ely, of Ely & Company, a financial consulting firm, in his comment on the proposal. The FDIC noted that banks with more than $50 billion in assets will pay 69% of the total DIF assessments, up from 59%. But the largest failure in recent years was Colonial Bank, which had $25 billion in assets and Indy Mac was the second largest at $23.5 billion. "There is a real possibility that the industry may litigate with FDIC over this issue, which we also noted as a primary concern in our comment," wrote Christopher Whalen of Institutional Risk Analytics. "The fact that most supervisory personnel with whom we interact at FDIC are very focused on risk-based measures for pricing assets and liabilities, but the deposit assessment rule lacks this component in many respects, is a striking anomaly that we have yet to understand. We shall be seeking to clarify this issue in coming weeks." Write to Jon Prior. Follow him on Twitter: @JonAPrior