Apple has named John Ternus as its new chief executive to replace Tim Cook who will become executive chairman at the technology giant.

Ternus, currently the head of hardware engineering who has been at Apple for 25 years, will take over from Cook on 1 September.

Cook has led Apple since 2011 after the late Steve Jobs resigned for health reasons.

He will stay as chief executive through the summer to work with Ternus on the transition after which he will "assist with certain aspects of the company, including engaging with policymakers around the world".

Cook's decision to step away from the chief executive role follows months of speculation that Apple was looking for a successor.

He described the job as "the greatest privilege of my life" and during his tenure he led the company to become one of the most valuable in the world.

In 2018, Apple became the first public company to be valued at $1 trillion (£740bn). It is now worth $4 trillion.

Cook described Ternus as a "visionary" executive with "the mind of an engineer, the soul of an innovator and the heart to lead with integrity and honour".

"He is without question the right person to lead Apple into the future," Cook added.

Ternus emerged as a favourite to replace Cook last year, after another long-time executive, chief operating officer Jeff Williams, left the company.

During his quarter century at Apple, Ternus has worked on essentially every major product the company has released, including every generation of the iPad, many generations of the iPhone, and the launch of AirPods and the Apple Watch.

He also oversaw the transition of Mac computer processors to Apple's own silicon.

Ternus also worked under Jobs, before his retirement in 2011 and death six weeks later. In a statement on Monday, he referred to Cook as his "mentor."

"I am filled with optimism about what we can achieve in the years to come," Ternus said.

Naming a leader who comes from a product and hardware background may allow Apple to emerge from a constant criticism of Cook's tenure, that it was no longer innovative enough.

While Cook oversaw a four-fold increase in Apple's yearly profit, with a massive expansion in products sold around the globe, it's product line has remained largely static.

Dipanjan Chatterjee, a principle analyst at Forrester, praised the financial stability Cook brought to Apple, but noted he had not given the company a product like the iPhone which would give Ternus another 20 years of success.

He said Apple "remains structurally dependent on the phone" as it "searches for its next growth engine".

The appointment of Ternus shows Apple is looking for "differentiation" in its products, said Chatterjee, adding that the new leader "must resist the temptation of incrementalism that has plagued Apple of late and escape the iPhone's gravitational pull".

Gil Luria, managing director at DA Davidson & Co, said having someone so hardware-focused at the helm now shows Apple is going put more energy into new products, like foldable phones and wearable devices like eye glasses.