One of the Swiss bank's key domestic bankers is departing after 21 years. 

Didier Denat is leaving Credit Suisse, the Zurich-based bank said in a statement on Tuesday. The head of corporate and investment banking in Switzerland has elected to resign in favor of a new professional challenge. Denat couldn't immediately be reached for comment.

The move comes tens months after Andre Helfenstein took over the Swiss unit, after previous head Thomas Gottstein was bumped to the top job at Credit Suisse following a spy scandal last winter. Denat is a 21-year veteran of the Swiss bank, and a member of its top management in Switzerland.

Corporate Replacement Ready

He will be replaced in the corporate job by Andreas Gerber (pictured below), effective January 1. Gerber currently oversees business with small- and mid-sized businesses in Switzerland.

gerbe 500

It isn't clear how Credit Suisse plans to replace Denat in the investment banking job. The Swiss banker is a capital markets veteran who began at Credit Suisse as a leveraged finance co-head in the wider European region in 1999.

He emerged as a linchpin in Credit Suisse plan to partially list the Swiss unit – ultimately canceled – as well as in its hunt for fintech prospects.