BlackRock Inc. is calling employees back to offices at least four days a week, telling staff that the firm has found benefits from working together in person after the pandemic.

The new policy will take effect Sept. 11, with flexibility to work from home one day a week, Chief Operating Officer Rob Goldstein and Caroline Heller, global head of human resources, said Tuesday in a memo to staff.

“Career development happens in teaching moments between team members, and it is accelerated during market-moving moments, when we step up and get into the mix,” the executives wrote. “All of this requires us to be together in the office.”

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The world’s largest asset manager rolled out its “Future of Work” pilot program in late 2021, when New York-based BlackRock said it expected more than half of its personnel to work in the office at least three days a week.

The firm had about 19,800 employees in more than 30 countries at the end of last year.

(Updates with headcount in final paragraph.)