The drivers of recent banking transactions are many of those that have shaped the European banking industry for the past 15 years: sluggish revenue outlook as the sugar rush of higher interest rates fades and rising costs as the promise of IT-driven efficiency is continually offset by higher investment spend,

Executives from UniCredit and Commerzbank held their first meeting on Friday, after the Italian bank this month emerged as the biggest investor in its German peer with a nearly 21% stake, subject to supervisory approval.

At 61 billion euros ($68 billion), UniCredit's market value is roughly three times Commerzbank's 19 billion euros. Shares in Germany's second-biggest publicly-listed bank have gained 30% since UniCredit unveiled its initial holding on Sept. 10, as markets bet on a full takeover.