Amazon said Tuesday that sales of its Kindle tablets and e-readers have more than doubled over the key weekend launching the holiday season, but provided no specific sales figures.
The online retail giant said "Cyber Monday," which is a major sales day following the Thanksgiving holiday, was "the biggest day ever for Kindle sales worldwide."
Amazon recently unveiled new models of the Kindle tablet, which has been one of the main rivals to the market-leading iPad. It announced an upgraded Kindle Fire HD, which is roughly the size of the iPad mini, as well as a larger version closer to the size of the original iPad.
Amazon also has begun selling the tablets in some international markets for the first time.
"The top four spots on the worldwide Amazon best sellers list since launch nearly three months ago are Kindle e-readers and Kindle Fires," the company said in a statement.
"Kindle Fire HD is the most gifted and most wished for product on Amazon worldwide since launch."
Dave Limp, vice president of Amazon Kindle, said, "We're excited that customers made this Black Friday and Cyber Monday the best ever for Kindle worldwide. Cyber Monday was the biggest day ever for Kindle sales, and we're looking forward to millions of customers opening a new Kindle this holiday season."
Amazon has never released detailed sales figures for the Kindles, but earlier this year said its Kindle Fire had captured 22 percent of the US market for tablet computers.
The statements suggest Amazon has sold several million Kindles in a market which is red-hot.
One survey predicted global sales of tablet computers are expected to surge to 126.6 million in 2012.