WASHINGTON(Reuters) - U.S. banking regulators are scheduled to vote on a proposal Tuesday morning that would govern banks' relationships with retail customers who speculate in the foreign exchange market.

Under the rule, recommended by the Federal Deposit Insurance Corp staff, retail customers who engage in foreign exchange transactions with a bank that are not cleared through an exchange would have to post a margin amount of 2 percent in the case of major currencies, and 5 percent of the notional value of the transaction for more exotic currencies.

The rule is required by the Dodd-Frank financial oversight law and it will be voted on Tuesday by the FDIC. (Reporting by Dave Clarke, Editing by Gerald E. McCormick)