Barnes & Noble has placed more orders for Nook Tablets with downstream suppliers and is expected to take deliveries of up to 1.1 million units of Nook Tablets as well as 400,000 units of Nook Color e-book readers in the four quarter of 2011, according to sources in the supply chain.

While Barnes & Noble has not yet decided whether to launch an upgraded version of Nook Tablet or new models with larger displays in 2012, the vendor has set a target to order 4.0-4.1 million 7-inch Nook Tablets for the year, the sources revealed.

Although PC and handset vendors including Hewlett-Packard (HP), Acer, Dell, RIM and Motorola Mobility have continued developing tablet PCs, their product roadmaps for the segment are still unclear, the sources commented.