ST. PAUL, Minn. (AP) - Gov. Mark Dayton's economic development chief is stepping down.

Dayton announced Thursday that Department of Employment and Economic Development Commissioner Katie Clark Sieben would step down April 22. It's unclear why she's leaving the job. She was appointed to lead the department in 2012.

The governor is filling the position with one of his top staffers, Deputy Chief of Staff Shawntera Hardy. Hardy had been tasked with helping diversify state government's workforce and managing emergency responses.

Her appointment is another nod to Dayton's vow to focus on closing longstanding racial economic gaps in Minnesota. Dayton says Hardy shares his goal.