Apple Computer has unveiled a pencil-thin "iPod nano" digital music player and a long-anticipated mobile phone that plays music like an iPod, both aimed at extending its domination of the digital music market.

The seriously slimmed-down nano - about a quarter of an inch thick, 3,5 inches long and 1.5 inches wide - drew "oohs" and "ahhs" from the audience at the product release in San Francisco, outdoing the buzz generated by the Rokr phone, which some said failed to meet high expectations for design.

The nano players, either all black or all white, are nearly as small as the entry-level iPod Shuffle but sport click wheels and hold up to 1,000 songs.

Apple, which has opened its second UK store in Birmingham's Bullring shopping centre, has about 75 per cent of the market for digital music players, with iPod sales about one-third of its total revenue, and Apple chief executive Steve Jobs said competitors had set their sights on the iPod mini, which he said was Apple's best- selling iPod model.

The nano replaces the mini, and Gartner analyst Van Baker said that Apple - which has sold 21 million iPods since introducing them in 2001 - has moved the goalposts much farther down the field with the nano.

"It changes the rules of the game," Baker said.

The iPod nano uses flash memory chips to store songs and photos, rather than the hard-disk drives that the iPod mini and the larger iPods use.

The Rokr phone is Apple's long-awaited foray into the wireless realm. Developed with Motorola, it can store up to 100 songs and has a colour screen, stereo speakers, stereo headphones and a camera.

Cingular will be the first mobile carrier for the Rokr. Several operators in the United Kingdom are expected to offer the phone soon.

But some said the silver phone did not meet style expectations set by Apple's iPod and Motorola's slim flagship Razr phone, and others cited its limited song capacity for iPod users accustomed to carrying thousands of songs.

"It doesn't have the emotive cachet that the Razr or the iPod has," said Yankee Group analyst John Jackson. "When you whip this out in the bar, nobody's going to say, 'That's a cool device.'"

The Rokr iTunes phone will be available in Cingular stores on Thursday.