The portable, all-in-one navigation device is to retail at an estimated price of $499, and the launch, in the home market of Garmin Ltd, is sure to attract the attention of its American rival.

TomTom ONE has been available in Europe for a while now, but TomTom has selected Dutch geographic content provider Tele Atlas NV as the data provider for the North American version.

TomTom ONE is similar to Garmin’s Nuvi 360 GPS device, and is described as an entry-level product designed for maximum portability. It measures 1.0 by 3.8 by 3.2 inches, and has a large 3.5-inch touch screen. Maps for the US, Canada, and Guam, based on Tele Atlas’s map data, are supplied on a 1GB SD memory card.

The North American market is hugely important to Amsterdam, Netherlands-based TomTom, which expects to sell between 3.6 million and 3.9 million portable navigation devices this year. It already has garnered a considerable customer base in the UK and Europe, but it has had limited impact so far in the US.

Garmin has been ramping up its European campaign, and it says that Europe is its fastest growing market, with particularly strong growth in the UK. The European business increased 83% in the second quarter.