MILAN (Reuters) - Mergers among Italian lenders could make the banking system more solid, Stefano Buffagni, cabinet undersecretary and a prominent member of the ruling 5-Star Movement, said on Wednesday.

The Italian government should play a leading role in engineering tie-ups with the goal of creating national champions able to compete on the global market, he said.

But the idea of merging troubled banks Monte dei Paschi BMPS.MI and Banca Carige CRGI.MI is not "sustainable", Buffagni, who is also sits in Parliament, said.