Apple Inc. announced Sunday that Tim Cook will step down as chief executive officer, ending a tenure that began in 2011 when he succeeded company co-founder Steve Jobs. John Ternus, Apple's senior vice president of hardware engineering, has been named as Cook's replacement, positioning a company veteran to lead the world's most valuable technology firm into its next chapter.

Cook, 65, oversaw a period of remarkable growth at Apple, during which the company's market capitalization soared to become the first to surpass $3 trillion. Under his leadership, Apple expanded its services division — including the App Store, Apple Music, and Apple TV+ — and steered the company through supply chain disruptions, trade tensions with China, and intense regulatory scrutiny across the United States and Europe.

Ternus, who has been with Apple for more than two decades, is widely regarded inside the company as a steady, technically proficient executive deeply embedded in Apple's product development culture. Analysts characterized the appointment as a continuity choice, designed to reassure investors and maintain the company's hardware-centered product roadmap at a time when Apple is making significant investments in artificial intelligence and augmented reality.

The leadership change comes as Apple faces mounting pressure on multiple fronts, including antitrust investigations, questions about its dependence on Chinese manufacturing, and competition in the AI space from rivals including Google, Microsoft, and a wave of newer entrants. Ternus inherits a company with a loyal global customer base but also significant strategic decisions ahead regarding how aggressively Apple pursues AI integration in its core devices.

Cook is expected to remain involved with Apple in an advisory or board capacity, though details of any ongoing role were not immediately confirmed. Apple did not specify an exact date for the formal handover of responsibilities.