* Debt recovery platform valued at 143 mln euros (Adds details, advisers): MILAN (Reuters) - Banco BPM (BAMI.MI) said on Monday it had agreed to sell up to 7.8 billion euros ($8.9 billion) in bad loans along with a stake in its debt recovery business to Credito Fondiario and U.S. fund Elliott, confirming what sources previously told Reuters.