Jon McNeill, who was hired last year to run Lyft Inc.’s operations, is leaving the company. The founders, who have struggled to retain an operating chief, said they won’t hire a replacement.

Before joining Lyft, McNeill was a deputy to Elon Musk at Tesla Inc. He spent two and half years at the automaker, where he served as president of global sales and service.

In an email to staff reviewed by Bloomberg, Lyft founders Logan Green and John Zimmer said they will reassign McNeill’s responsibilities to other employees. They credited the COO with establishing new businesses, including car repair shops for Lyft drivers. “As JMac moves on to his next chapter, we wish him the very best,” the founders wrote.

Lyft shares (LYFT) fell as much as 3.9%, the biggest intraday decline in a month, to $62.94 after Bloomberg News first reported McNeill’s departure.

The ride-hailing company, which is run by Green and Zimmer, has struggled to keep experienced lieutenants. McNeill’s predecessor, former Amazon.com Inc. executive Rex Tibbens, lasted less than three years. When Lyft hired McNeill in February 2018, it touted his experience and welcomed him to the “Lyft family.”

Lyft went public in March, and the stock currently trades about 10% below the initial public offering price. Investors have questioned the sustainability of the money-losing ride-hailing business, which has also put pressure on Uber Technologies Inc.