Sony has quietly entered the e-reader price war by significantly reducing the price of its popular device from $349.99 to $299.99, just days after both Amazon and Barnes & Noble cut the prices on their devices. As a report in the Financial Times notes, “The pricing moves by the three e-reader pioneers comes as Apple’s iPad table computer threatens to eat into the market, which is expected to more than double to 5m units this year from 2.2m last year.”

Sony’s e-reader is the second most popular device, after the Kindle, with approximately 30-35% of the market, says the FT. It credits Amazon with control of 60-65% of the e-reader market.

As the FT report recaps,

Without that cut, Sony’s top-end e-reader would have been close in price to Amazon’s most expensive Kindle, the Kindle DX, which came down in price to $379 from $489.

Amazon has also lowered the price of its cheaper version of the Kindle to $189, while Sony also cut the prices of its Touch Edition to $169.99 from $249.99 and the basic Pocket Edition to $149.99 from $169.99.

Barnes & Noble had kicked off the price cuts last month by lowering the price of its Nook to $199.

According to the FT, most of these moves are motivated by fear that “the iPad, which can also function as an e-reader, will take a significant share of the market ….”