Aflac said it entered into agreements to swap into Japanese yen the $750 million in dollar-denominated senior notes that the Columbus, Ga.-based insurer issued Feb. 10. The agreements cover $400 million of 5-year fixed-rate notes as well as $350 million of 10-year fixed-rate notes. The swap arrangement “significantly lowers the effective interest rate on the senior notes ... and provides future flexibility with our capital position,” said President and Chief Financial Officer Kriss Cloninger in a statement.