ZURICH, May 13 (Reuters) - UBS will reinvest part of 13 billion euros ($14.03 billion) in planned cost savings on making the bank's processes and businesses stronger following the takeover of Credit Suisse, UBS chief executive Sergio Ermotti said on Monday. ($1 = 0.9268 euros) (Reporting by Elisa Martinuzzi and Noele Illien, Editing by Rachel More and Friederike Heine)