Italian bank Mediobanca on Tuesday rejected a takeover offer by state-backed rival Monte dei Paschi di Siena , saying a tie-up would be detrimental to its shareholders because it lacked any strategic and financial rationale.

Mediobanca’s board will meet on Tuesday morning to evaluate the unsolicited approach, which has garnered government support but so far failed to win over investors and analysts.

Tuscany's bailed-out Monte dei Paschi had unexpectedly launched a 13-billion-euro all-share takeover proposal for Mediobanca.