Apple’s (AAPL) longtime chief financial officer (CFO) Peter Oppenheimer, perhaps the least visible of the vendor’s top executives, will retire from his executive post in September and segue to Goldman Sachs as one of its 13 board members.

Oppenheimer, an 18-year company veteran who has served as Apple’s CFO for the past decade and whose public appearances largely have been confined to Apple’s quarterly earnings calls, will be replaced by Luca Maestri, current Apple Finance vice president and corporate controller, who will take the post in June, reporting to chief executive Tim Cook.

Cook praised Oppenheimer’s work and said Apple had Maestri in mind as the CFO’s replacement ever since he joined the vendor a year ago. Maestri, who came to Apple after CFO stints at Nokia Siemens Networks and Xerox, commands some 25 years of experience in senior financial management.

“[Oppenheimer’s] guidance, leadership and expertise have been instrumental to Apple’s success, not only as our CFO but also in many areas beyond finance, as he frequently took on additional activities to assist across the company,” said Cook “His contributions and integrity as our CFO create a new benchmark for public company CFOs.”

Cook believes Maestri can fill Oppenheimer’s shoes. “When we were recruiting for a corporate controller, we met Luca and knew he would become Peter’s successor,” he said.

Soon after his hiring Maestri was granted restricted stock valued at about $16 million.

A large portion of Maestri’s experience comes from his 20 years at General Motors in finance and operating roles in the Americas, Asia Pacific and Europe. While at GM, he was credited with helping to set up the company’s regional operations in Asia Pacific, later served as CFO of the team that restructured operations in Brazil and Argentina, ultimately rose to CFO for all of GM’s operations in Europe.

Oppenheimer joined Apple in 1996 as controller for the Americas and one year later was promoted to vice president and worldwide sales controller and then to corporate controller prior to taking the CFO job.

“I love Apple and the people I have had the privilege to work with and after 18 years here, it is time for me to take time for myself and my family,” Oppenheimer said.