Apple has updated its iPhone X handset with three more powerful models, two of which are larger than before.

The iPhone XS Max has a 6.5in (16.5cm) display. The iPhone XS has the same 5.8in-sized component as the original. The iPhone XR's screen is 6.1in but is lower quality.

A new smartwatch was also launched with an added fall-detection function.

There had been concerns that the relatively high £999 entry price of iPhone X would limit its appeal.

But Apple said it had consistently proven more popular than either of the lower-priced iPhone 8 models. Market research firms suggest it also outsold rival companies' flagship devices.

That helped propel Apple to become the world's first company with a market capitalisation above $1tn (£768bn).

However, China's Huawei still managed to overtake it in terms of overall smartphone market share in the April-to-June quarter, putting Apple into third place.

"Huawei was able to overtake it because Apple is not playing in the mid and low ends of the market," commented Francisco Jeronimo from IDC.

"But Apple is very well positioned in the premium segment, and we don't expect that to change over the next 18 months."