Baidu Inc. (NASDAQ: BIDU) on Friday announced that Qi Lu will step down from chief operating officer, sending the stock down more than 7 percent.

Lu, a former executive at Microsoft, joined Baidu in January 2017. The company said Lu will no longer serve as COO starting in July 2018 and will continue to serve as vice chairman of the board of directors.

Since Lu took over the operational management at Baidu, he joined the company to reposition Baidu as an AI-first company. Baidu is known as the search service provider before.

"I have deeply enjoyed working with Robin and my team at Baidu. I'm honored to have participated in Baidu's transition into an AI-first company. Due to personal and family reasons, I am no longer able to work in China on a full-time basis," said Qi Lu. "Baidu is a great company with strong talent and deep technologies. I am highly optimistic on Baidu's future and will continue to support Baidu, while spending more time with my family in the U.S. For my next steps, I plan to work in research and investment areas, to help advance our shared mission to make a complex world simpler through technology."

Baidu has been trying to find new growth drivers in the recent years. The company continued to invest in Al-enable new business initiatives, such as Al-cloud, financial services, DuerOS, and autonomous driving. The company also announced to spin off its food delivery business to better focus on its Al business.

Baidu shares fell 7.59 percent to $258.45 in the early trading on Friday after it hit all-time high in the previous trading session.