Apple has announced that Tim Cook will step down as chief executive on September 1 after nearly 15 years leading the Cupertino, California-based technology giant, with John Ternus, the company's head of hardware engineering, named as his successor. Cook, 65, will remain with the company as executive chairman — a transition similar to those made by Amazon's Jeff Bezos and Netflix's Reed Hastings after their own departures from the top job.

The announcement, made on Monday, ends months of speculation about succession at one of the world's most valuable companies. Cook, who took the helm in 2011 following the death of Apple co-founder Steve Jobs, oversaw a period of extraordinary financial growth. Under his leadership, Apple's market value rose by more than $3.6 trillion, driven by the dominance of the iPhone and the expansion of services, wearables, and a tightly integrated technology ecosystem. Last year the company reported revenues of $416 billion and net profits of $112 billion. Its market capitalisation now stands at more than $4 trillion.