Online retailer Amazon.com is making its popular wireless reading device, the Kindle, available to UK residents for the first time.The device, due to go on sale in Europe on 19 October, will only be available at first from the US site, Amazon.com. It retails for $279 (£175) + $3.99 shipping, and ships with a US power adapter. The company plans to introduce a Kindle tailored to the UK market and available from its UK site with a price quoted in sterling, though it has not revealed when it expects this device to be available. Amazon has also cut the price of the most basic model of the Kindle by $40 to head off competition from rival electronic book devices such as Sony's e-reader and Interead's Cool-er. The e-reader pocket edition retails at about £160 ($254) and the Cool-er can be bought for £189 ($300), though US customers can buy it for $249.The number of books available for download to non-US Kindle owners will be lower at about 200,000 titles, compared to 355,000 available to US customers. The downloads will be via the 3G wireless telephony network, though transfers can also take place via a USB (universal serial bus) device.Books in digital format are becoming increasingly popular. Amazon says that where it sells books in both digital and physical formats, it sells 48 digital copies for every 100 physical copies, up from a ratio of 35:100 five months ago.The release of the Kindle in the UK represents a challenge to HMV owned Waterstones, which sells e-reader format books via its web site.