The Italian lender, UniCredit, is reportedly preparing to file an application with the European Central Bank (ECB), seeking approval to increase its stake in Germany’s Commerzbank AG to as much as 30%, according to a report by Il Messaggero on Tuesday. The news spurred a surge in Commerzbank shares, reaching €15.85 before a slight pullback – a level not seen since 2012. UniCredit’s shares also gained 0.6% following the news. Initial stake acquisitionThis move follows UniCredit’s recent acquisition of a 9% stake in Commerzbank last Wednesday. The Italian bank purchased 4.5% from the German gove…