The last time Banca Monte dei Paschi di Siena SpA bought another lender, it was the beginning of the road to collapse and nationalization.Most Read from BloombergWhat Happened to Hanging Out on the Street?

By Valentina Za and Gianluca Semeraro MILAN (Reuters) -State-backed Monte dei Paschi di Siena on Friday joined in the consolidation wave sweeping Italian banking with a surprise 13.3 billion euro ($14 billion) all-share offer to buy merchant bank Mediobanca.

The surprise move is the latest amid a wave of consolidation in the country’s banking industry in recent months and would create Italy’s third-largest entity in the sector.