Wall Street banks got a one-year reprieve from rules that would subject derivatives trades held overseas to tough U.S. oversight.

The delay announced Thursday by the Commodity Futures Trading Commission exempts some transactions set up in the U.S. to Dodd-Frank Act regulations until Sept. 30, 2017, as long as the trades are held in foreign affiliates.

The decision to postpone the policy, which has already been delayed several times, is the latest twist in an ongoing battle between large banks and the U.S.'s main derivatives regulator over how to apply rules to trades held overseas. Separately, the agency said in a court filing it had laid out the costs and benefits of several swaps rules that the industry has tried to prevent from being applied outside U.S. borders.