Intel unveiled a new category of laptops that it says will include the best features of tablets as the world?s top chipmaker struggles to help the personal-computer industry fend off a challenge from Apple?s iPad and other tablets.

At the Computex technology exhibition in Taipei ? Asia?s biggest IT trade fair ? computer maker Asus is expected to show off its first new PC in the ?Ultrabook? class, and Intel said it and models made by other manufacturers would go on sale by Christmas and cost under $1,000.

This came even as two electronic firms unveiled new tablet computers in Taipei on Monday, on the eve of the IT trade fair, as they try to get a slice of a lucrative market dominated by iPad.

The Ultrabooks will be svelte and lightweight but still pack high-performace processors. The new machines will be less than an inch thick, have days of battery life on standby, start up in just seconds and retail for less than $1,000, according to Intel executive vice-president Sean Maloney, who will discuss the products at a speech later on Tuesday. Intel aims to convert 40% of consumer laptops to the new category by the end of 2012.

?We?re shooting for ultra responsive. You?ll have always-on, always-connected, much more responsive devices, similar to what you would see with a tablet today such as an iPad,? said Tom Kilroy, a senior vice-president at Intel, said in an interview. Kilroy also added that prices for Ultrabook laptops would likely fall to around $600 within a couple of years.

Santa Clara, California-based Intel is eager to make laptops more attractive to consumers who are increasingly captivated by Apple?s iPad and other mobile gadgets.

Its processors power 80% of the world?s PCs but Intel has failed so far to adapt them for smartphones and tablets. Manufacturers like Motorola and Apple favour processors made using energy-efficient technology licensed by Britain?s ARM Holdings.

While Intel also is developing new chips for tablet computers, the company has struggled to translate its PC dominance into success in that market. Apple?s device runs on mobile-phone chips, rather than Intel processors. Tablets from Samsung Electronics, Motorola Mobility Holdings and Research In Motion also rely on non-Intel chips.

Until now, ultraportable devices from PC makers haven?t sold well because of high prices and chips that didn?t deliver enough performance, Maloney said in an interview. ?We want to find new ways to propel the PC forward,? said Maloney, who is taking on a newly created position as chairman of Intel China. ?With what has happened in the tablet space, there is a ?hurry-up? to the PC industry.?

This month, Intel took the wraps off next-generation ?3D? technology that crams more transistors onto microchips, betting it will eventually become a significant advantage in tablets and smartphones.

Intel also plans to shrink the circuits on its mobile chips by three sizes within three years ? a faster pace than normal ? to make them much more efficient.

Kilroy declined to comment on recent speculation that PC maker Acer is planning to launch a tablet within months using Intel?s brand new Oak Trail chip and Google?s Android operating system. Acer could not be reached for comment.

Such a device would be a major test of Oak Trail, Intel?s first chip designed specifically for tablets and able to support the widely popular Android platform.

The Ultrabook is not the first PC category that Intel and Asus have promoted together. In 2007, Asus introduced a small and simplified laptop that is widely viewed as the first of many low-cost ?netbooks? geared toward surfing the internet.

Intel expects to have 35 tablets based on its chips on sale by the end of the year. It will demonstrate 10 of them during Maloney?s speech at the Computex industry show in Taiwan.

Maloney will be joined on stage by Asustek Computer chairman Jonney Shih to demonstrate that company?s UX21 ASUS ultrabook computer. Later generations of ultrabooks will be based on Intel?s new processor design, called Ivy Bridge.

As thousands of industry delegates prepared for the Computex Taipei fair, US firm ViewSonic and Taiwan?s Shuttle showed off their latest innovations.

ViewSonic, a visual technology firm based in California, introduced what it said is the world?s first tablet that is equipped with both Windows 7 and Google?s Android platforms.

?While iPad users are aimed for entertainment, our new machine has functions more than that,? Kai Wang, a ViewSonic product manager, said during a news conference on the eve of the five-day event.

Kai said the ViewPad 10 Pro will be a simple transition for people who are already used to Microsoft?s operating system, adding that he expects much of its customer base to come from those who already use netbooks.

The new tablet, ViewPad 10 Pro, weighing slightly more than 830 grams, will hit the Taiwan market in June and elsewhere in the Asia Pacific in July, with a price tag of up to $799.

IT firm Shuttle from Taipei, meanwhile, showed off its low-priced gadget aimed at the student market.

On unveiling the Shuttle V08, company manager Donald Chen told journalists: ?It?s true iPad is popular, but it is impossible for Apple to take the world?s entire tablet market. There is still room for some tailor-made tablet developers.?

With anti-dust and waterproof characteristics, its tablet weighs only 650 gram and is slated to cost just $200.

?Can you see how big the market will be as long as competitors can grab up to a 30% share of the global tablet market?? Chen said.

Worldwide sales of tablet computers are forecast to hit 50 million units this year and double to 100 million in 2012, said Chang Li from the Taipei Computer Association, which co-hosts the annual trade fair.

Even as the tablet war is at its peak, the technology in personal computers is changing, threatening company like Avidia?s old market. Intel and Advanced Micro Devices both sell main processors that include graphics abilities, cutting out the need for add-on graphics processors.

Computex Taipei, which runs from Tuesday until Saturday, is the second biggest information technology and communications trade show in the world and attracts thousands of exhibitors from around the world.