Apple reported the largest net profit ever for a public company in the three months to December, powered by 74.5 million iPhone sales.

Strikingly, the contribution of the iPhone to Apple’s total revenue leapt to 69 per cent in Q1 2015 from 56 per cent a year earlier.

However, the quarterly numbers also told another story – the waning influence of the iPad whose share of total revenue fell to 12 per cent from 20 per cent. Unit sales have dropped to 21.4 million from 26 million a year earlier.

The US giant delivered net profit of $18 billion in the three months to 27 December, while quarterly revenue hit $74.6 billion.

This compares with net profit of $13.1 billion and revenue of $57.6 billion in the year-ago period.

China flexed its muscles but, contrary to predictions, failed to overtake the US as Apple’s largest market for the iPhone, expressed in unit sales.

Revenue from China grew by 68 per cent to $16 billion, which is still barely half that of the Americas with $30 billion, a figure which grew just 14 per cent.

Apple has now accrued a cash pile of $178 billion, which would be sufficient to purchase IBM such is its size.

On the iPad, Apple CEO Tim Cook (pictured) remained “very optimistic and bullish” in the long run, according to comments on the analyst call, pointing to first-time buyer rates.

In markets including the US, UK and Japan, 50 per cent of iPad buyers are first timers, pointing to a sustainable market for the tablet, he said. Cook also argued the upgrade cycle for an iPad is longer than for an iPhone.

On November 22 2014, Apple shipped its one billionth iOS device, which Cook described as “an almost unfathomable milestone”.

He said results would have been even stronger, if not for foreign currency fluctuations.

Looking forward, Apple’s CEO said development of the Apple Watch was “right on schedule” and the company expects to begin shipments in April (the company originally talked about early 2015 launch).

He said developers are working on apps, notifications and information summaries called Glances, that are designed specifically for the Watch’s user interface.

Cook was also asked about Apple Pay and how the NFC-based payment service might evolve (it only launched at the end of 2014). He answered that the service, which is only available in the US, was still in its “first innings” and commented there is “a ton of things on our roadmap for adding functionality to it”.