Having promised a new consumer product that is "innovative, revolutionary and different", Apple is expected to take the wraps off a redesigned iMac today which looks more like a desk lamp than a desktop computer.

The original, bubble-like iMac was an instant hit when it was unveiled in 1998. The colourful computers have been credited with saving Apple from the doldrums it had settled into during the mid-1990s. But over time, some analysts said the iMac's design had become stale and was in need of a fresh look to boost sales.

Details of the new iMac have been scarce, with Apple officials remaining tight-lipped as to what users can expect the company to unveil at this week's Macworld Expo in San Francisco. The Mac, however, is already out of the bag.

The design of the new iMac is a radical departure from the previous version. Its base is a small, halved sphere that measures 26.4cm in diameter, according to a report in Time magazine. A flat-panel monitor is attached to the base using a jointed chrome neck that can be adjusted to position the monitor. The monitor itself is ringed by a translucent plastic 'halo' while the rest of the case and the base is white plastic.

The new iMac, prices for which start at just over £900 ex VAT, includes a raft of multimedia software applications and, in the top-of-the-range model (an extra £350), a DVD (digital versatile disc) burner, Time's report said.

The iMac will ship with iDVD, which allows users to make DVD movies, iMovie, a video editing application, iPhoto, a digital photo-editing tool and iTunes, which lets users convert CD music into MP3 files and can synch with Apple's iPod portable MP3 music player, said the magazine.

The Time article, however, did not reveal several key technical features of the new iMac, including what processor the computer uses, the amount of main memory it has, how big the hard disk drive is and whether it offers built-in support for wireless networking protocols such as Bluetooth or 802.11b.