MILAN, March 22 (Reuters) - BPER Banca's largest investor on Friday put forward former UniCredit executive Gianni Franco Papa as the candidate to take the top job at Italy's fourth-largest lender.

BPER shareholders will meet to name a new board on April 19.

The bank's top investor, insurer Unipol, is proposing replacing CEO Piero Montani, a turnaround expert that BPER brought in to oversee integration of businesses it bought in recent years.

Unipol, which owns nearly 20% of BPER, said it would submit a slate of seven candidates for the bank's board, including Gianni Franco Papa, who already sits on BPER's board, as the first name on its proposed list.

It is customary that if the list is voted, the first candidate on it is designated as CEO of the bank.

Gianni Franco Papa, 67, was a former director general at UniCredit, where he held various senior roles mostly in Eastern Europe, before joining BPER's board in 2021.

Unipol, which also holds around 20% of smaller bank Banca Popolare di Sondrio, has been working to widen BPER's footprint to secure a bigger distribution network for its products. (Reporting by Andrea Mandalà; Editing by Gianluca Semeraro and Shounak Dasgupta)