The Swiss bank is handing the reins of its business with America's wealthy to a long-standing partner at Deloitte in Switzerland.

Zurich-based Vontobel is hiring Jacqueline Hess as CEO of Vontobel Swiss Wealth Advisors, its private banking entity for U.S. clients, it said in a statement on Tuesday. Her appointment is effective by August 3.

Hess replaces Patrice Humbel, who is retiring after holding the job for the past three years. The 66-year-old Swiss banker will remain a vice-chairman at Vontobel for U.S. clients, the bank said.

Hess, a lawyer who has been with Deloitte since 2005, is current managing partner of its tax and legal practice. Nearly ten percent of Vontobel's overall assets are from clients in North America, a major growth market for the Swiss bank.