FRANKFURT (Reuters) - Commerzbank’s chief executive believes a strong and focused investment bank would be a good addition to the lender, according to a person familiar with his thinking on Friday.

The person, speaking on condition of anonymity, revealed Chief Executive Officer Martin Zielke’s thinking as Commerzbank talks about a possible merger with Deutsche Bank , which has a sprawling global investment bank.

Separately, Zielke promised employees on Friday a quick decision on whether to go forward with the merger, according to a memo seen by Reuters.

“I can promise you that we will strive to keep this period of uncertainty as short as possible and we will work hard to ensure that a decision is reached soon,” Zielke wrote.

Zielke said Commerzbank had a clear idea of how it could develop business in a sensible way. “This is the reason why we are in conversations with Deutsche Bank,” he said.