Sony Corp. unveiled five new Walkman music players Thursday in an attempt to challenge Apple Computer and its iPod line of digital media devices.

The new lineup includes three flash-memory-based models with capacities of 512 megabytes (MB) (NW-A605), 1 gigabyte (GB) (NW-A607)and 2GB (NW-A608), and two hard-disk drive-based models with capacities of 6GB (NW-A1000) and 20GB (NW-A3000). Sony said its new Walkman models will start selling in Japan November 19.

Contrary to other published reports, The Mac Observer has learned the new Walkman devices will be introduced in the U.S. and Europe by the end of this year.

All the new players have OLED displays and support the MP3 and ATRAC3plus file formats. The flash-based players have built-in FM radio and are rated at 50 hours of battery time before re-charging. The 6GB model will come in violet and silver colors, while the 20GB model will be available in pink and blue. The models also will randomly play the 100 most listened to songs and play at random songs from a specific time period.

In terms of today's currency rates, the 512MB Walkman will retail in Japan for US$199, the 1GB at $244, the 2GB version at $289, the 6GB model at $271, and the 20GB version at $316. Exact North American pricing has not been announced.

The new Sony products come one day after Apple updated its iPod lineup with the ultra-thin music player, the iPod nano.

Koichiro Tsujino, the head of Sony's music player and service business, told The Wall Street Journal he doesn't know much about Apple's new products yet, but with the new Walkman models, "we believe we can compete well."