Google CFO George Reyes plans to leave the company at the end of the year.

Google announced Tuesday that Reyes would step down after assisting in a search for a replacement.

"I've known and admired George since our days together at Sun," Google chairman and CEO Eric Schmidt said in a statement. "As Google's CFO, George successfully navigated our innovative IPO, the regulatory demands of Sarbanes-Oxley, and the management challenges of scaling a global finance organization. Though we fully appreciate his decision to step back from active management, we'll miss his thoughtfulness, good humor, and wisdom."

Reyes characterized his five and a half years at Google as "an extraordinary ride." In a statement, he said, "I'm honored and flattered to have been a part of this great management team. I know I'm leaving the company in good hands with a remarkable team of professionals that will continue to build on Google's tremendous achievements."

Google co-founder Larry Page, in a statement, lauded Reyes for keeping Google financially disciplined while protecting the company's entrepreneurial culture.

Reyes joined Google as CFO in 2002. Previously, he served as interim CFO of optical networking company ONI Systems, which was acquired by Ciena. Before that, Reyes worked at Sun Microsystems for 13 years.

Reyes serves on the boards of directors at Symantec and BEA Systems.

Reyes' departure comes following a lackluster quarter for Google. Despite strong advertising revenue, Google's second-quarter results were widely seen as disappointing, and the company's stock has remained basically flat since then.