Best Buy plans to sell an iRex Technologies e-reader that links to the Barnes & Noble digital bookstore, the electronics retailer and e-reader maker said on Wednesday.

The device from iRex, a spin-off of Royal Philips Electronics

, will have an 8.1-inch touchscreen and will sell for $399 when it goes on sale at Best Buy later in the fall under the iRex DR800SG brand.

The gadget will compete in the hot market for digital book readers with rivals such as Kindle from Inc and e-readers from Sony Corp <6758.T>.

Brick-and-mortar booksellers such as retailer Barnes & Noble are looking to digital books to help them battle a slump in sales in the $25 billion U.S. book market as readers go on line or turn to visual entertainment.

In July Barnes & Noble unveiled its online bookstore, which will be the exclusive provider of digital books to another e-reader from Plastic Logic. That device will have a wireless connection to AT&T Inc network.

The iRex device will deliver books wirelessly via Verizon Wireless, owned by Verizon Communications and Vodafone Group Plc , Best Buy and iRex said.

U.S. network operators have been looking to connect a wide array of consumer electronics and industrial devices to their networks in a bid to expand service revenues beyond cellphone connections as most people already have mobile phones.

(Reporting by Sinead Carew in New York and Harro Ten Wolde in Amsterdam, editing by Dave Zimmerman)