All major Italian banks beat market expectations for second quarter profits this week, helped like other European lenders by shrinking loan losses and rebounding revenues as the coronavirus crisis eases.
A Milan-based trader said shares in both BPER and Banco BPM were responding to the earnings, with fresh speculation about potential mergers and acquisitions fuelling gains.
Shares in BPER closed up 10.7% at a one-month high, the biggest rise on Milan's blue chip index.
Banco BPM, Italy's third-largest bank, rose 7.3%, also to the highest level since early July.
Both stocks were heavily traded, with volumes more than three times the average of the past 30 days.
(Reporting by Giancarlo Navach; Writing by Valentina Za; Editing by Maria Pia Quaglia and Mark Potter)