By Reuters Staff 2 Min Read MILAN, Feb 18 (Reuters) - Italy’s Banco BPM and the biggest investor in BPER Banca have begun working on a potential merger of the two banks that could be launched in the second half of 2021, La Stampa daily reported, citing unnamed sources. Banco BPM Chief Executive Giuseppe Castagna and Carlo Cimbri, the head of BPER Banca’s top shareholder Unipol , are in talks on the governance such merged entity could have, the paper said. The potential tie-up was spearheaded by Banco BPM Chairman Massimo Tononi and could “count on the support of some important sharehold...