(Bloomberg) Banco Santander SA opted not to redeem a €1 billion ($1.1 billion) additional tier 1 bond, an unusual move even amid the turbulent market for bank debt this year.Most Read from BloombergUS Health Officials Urge Moving Pot to Lower-Risk CategoryUBS Flags Cost Cuts After $29 Billion Credit Suisse WindfallHong Kong to Shut Down City Before Super Typhoon Saola HitsEurope's Biggest Oil Company Quietly Shelves a Radical Plan to Shrink Its Carbon FootprintCathay Expects to Suspend Hong K