Starbucks said Wednesday its former chief executive Howard Schultz will step down from the coffee chain's board of directors "as part of a planned transition."

Schultz, who ended his third stint as CEO in March, helped transform the brand from a small coffee shop into an international chain over the decades.

"I look forward to supporting this next generation of leaders to steward Starbucks into the future as a customer, supporter, and advocate in my role as chairman emeritus," the longtime Starbucks leader said in a statement.

In 2017, Schultz stepped aside as chief executive after his second tenure, handing the reins to Kevin Johnson. He later announced his retirement from the company and weighed a run for US president.

When Johnson left in 2022 after five years at the helm, Schultz returned as interim CEO, before Laxman Narasimhan took over the position in March this year.

In the company's statement on Wednesday, it also announced that Wei Zhang, most recently a senior advisor to Alibaba Group, has been elected to the board of directors effective 1 October.

Starbucks has in recent times come under fire over its confrontational approach to unionization, with Schultz defending against allegations it had violated US labor laws in countering the campaign.

In a hearing convened by progressive Senator Bernie Sanders earlier this year, Schultz said he was unaware of instances where workers were fired or relocated to other stores because of union activity.

Today, the Seattle-based corporation has more than 36,000 stores in 86 markets globally, according to the company.