NEW YORK- Starbucks Chief Executive Officer Kevin Johnson will retire on April 4, the company said on Wednesday, and the coffee chain's founder Howard Schultz will serve as interim CEO.

Johnson had signaled to the board of directors a year ago that he might retire when the COVID-19 pandemic waned, he said in a company statement.

After the pandemic shuttered Starbucks cafes around the globe, the company, under Johnson's watch, said it would start building some smaller stores with less room for seating and more emphasis on to-go and drive-thru orders.

Customers also placed more orders through the Starbucks mobile app, but that has led to long lines and overworked employees in some areas.

That barista burnout, as well as accusations by some workers that they were not getting enough protection from the deadly virus when at work, contributed to a surge of union organizing in U.S. locations.

On Tuesday, a federal labor board accused Starbucks of unlawfully retaliating against two employees in a Phoenix, Arizona cafe for trying to unionize their store.

Johnson has been at Starbucks for 13 years, the last five as CEO.

In a letter to employees on Wednesday, Johnson said that he has "fond memories of making beverages together, laughing together, and sharing stories with one another."

The company said it would provide more information during its annual shareholder meeting later on Wednesday.

The board expects to have selected a new leader by the fall, with help from executive search firm Russell Reynolds Associates, which it enlisted in 2021.

(Reporting by Hilary Russ; editing by Jason Neely and Nick Zieminski)