Apple is offering free upgrades for life on its operating system and business software, and unveiled thinner iPads and faster Mac computers ahead of the key Christmas season. 

The debut of the lighter iPad Air and MacBook Pro with sharper 'retina' display repeats a pattern of recent launches with improvements in existing lines rather than totally new products.

Apple said upgrades to its Mac operating system and iWork software suite, which compete with Microsoft products, will now be offered for all MacBooks and Mac computers.

That brings Apple's model of free system software upgrades on phones and tablets to the computer market, where Apple is still the underdog to Microsoft's Windows.

Apple may be trying to safeguard its grip on mobile software as Microsoft revs up its Windows-powered Surface Pro, which runs applications, such as Word or Excel, that are the standard for business customers, analysts said.

"We are turning the industry on its ear, but this is not why we're doing it," Apple's chiefeExecutive Tim Cook told media and technology executives in San Francisco. "We want our customers to have our latest software."

The market is awash in inexpensive tablets running Google's Android software, but the company may be focused on fending off a threat from the high end.

Gartner estimates that Apple's share of the global tablet market will slip to 47.2% in 2014, with Android-based tablets just overtaking Apple's this year. The IT research outfit expects Microsoft tablets to grab 3.4% of the market this year, double the 1.7% forecast for 2013.

Apple's new iPads are equipped with faster processors and better screens. Cook, at an industry conference in May, had hinted at "several more game changers" from Apple which could include wearable computers, but had not given a time frame.

Apple's new iPad Air - its full-size tablet - is about 20% thinner than the previous generation of tablets, weighs one pound and starts at $499. It will go on sale on November 1. The iPad mini now has a "retina" high-resolution screen. 

The two new tablets would face stiff competition, with Microsoft, Nokia and Amazon.com all plugging rival devices in coming months.

Apple also showed off a new Mac Pro, a premium and high-powered cylindrical desktop computer that will be assembled in US. It had shown the computer at a previously event.

Apple said it will first launch the new iPads simultaneously in the US and China, its biggest market, which is also a key growth region. It has already come under increasing pressure from cheaper devices ranging from Amazon's Kindle Fire to Samsung Electronics Note.

But while Apple is ceding market share to rivals, its superior library of apps and content should safeguard its lead for years to come, analysts say. Longer term however, investors hope to see real device innovation from a company that has not unveiled a new breakthrough product in years.

Cook yesterday dismissed the competition as directionless. "Our competition is different: they're confused," he said. "Now they're trying to make PCs into tablets and tablets into PCs. Who knows what they'll do next?"

"We have a very clear direction and a very ambitious goal. We still believe deeply in this category and we're not slowing down on our innovation," he added.