Business Insider understands the move had been planned for some time and a HSBC spokesperson told Adweek Clark is staying on to oversee the handover before a replacement is found.
His departure comes six months after Business Insider reported the bank laid off staff within its London-based global marketing department, including the marketer leading that division, Amanda Rendle. She had also been with HSBC for 15 years.
Separately this week, Reuters reported HSBC is set to cut "dozens" of jobs in its investment banking division.
Clark joined HSBC as its head of brand strategy in 2001 from advertising agency Saatchi and Saatchi. In 2006 he was promoted to head of marketing and customer experience. He was promoted again to 2010 to group head of marketing.
