Commerzbank AG CEO Martin Zielke told employees that a quick decision would be made on a potential merger with Deutsche Bank AG, according to a memo seen by Reuters.

Zielke promised that the "period of uncertainty" would be short and that a decision would be taken soon. The lender's CEO considers a strong investment bank a good fit, a person familiar with the matter told the newswire.

Deutsche Bank is in talks with local peer Commerzbank over a potential merger, which could create an entity with an equity market value of more than €25.6 billion.

Deutsche Bank banned its top managers from selling stock in the company, as part of normal procedure while it continues the merger talks, the Financial Times reported March 24. Deutsche Bank shares were placed on an "internal conflict list" following attempts by bankers to sell their shares in the company at the end of a mandatory lock-up period in March, multiple insiders told the newspaper.

A Deutsche Bank spokesman told the newspaper that the limitations are standard practice and "have since been narrowed to a smaller group," including senior staff privy to sensitive merger information.