Internet retailer Amazon is continuing its global expansion after quietly opening its Kindle eBook store in China together with the launch of Kindle apps for Apple's iOS and Android devices.

The new Chinese version of the Kindle Store could pave the way for the launch of the Kindle e-reader in the country which only recently received authorization from Chinese regulators.

Four Kindle models, including the Kindle Touch and Kindle Fire, as well as one Kindle keyboard, received approval from the State Radio Regulation of China, the regulatory body for radio and wireless products, in June this year.

Amazon hasn't commented on the arrival of its eBook store or the Kindle apps in China, however, all the details are available on its Chinese Web site.

The store, still in beta version, offers books mainly in Chinese with a recommended list from the Chinese newspaper, the Beijing Times. There are around 22,500 Chinese eBooks available for purchase on the site which also introduces Amazon's cloud-based Whispersync technology. The service synchronizes eBook activity, such as last page read, bookmarks, notes and highlights across all a user's devices running Kindle apps and eBooks downloaded from Amazon.

In October, Thomas Szkutak, Amazon's chief financial officer, said China was a great long-term opportunity for the company.

"You shouldn't be expecting high returns on invested capital in the short run, in that geography, but very exciting from a long-term perspective," said Szkutak in a conference call.

China's e-reader market is dominated by Hanwang Technology e-readers and Shanda Cloudary's Bambook. Amazon will also compete directly with with E-commerce China Dangdang and 360buy, both of which have platforms to sell eBooks in country.

The launch of Amazon's Kindle Store in China follows similar moves in Brazil, which was the first market where the internet retailer opened a digital store for books without releasing a Kindle device. That store started operation at the start of December and offers a range of Portuguese language eBooks.

Amazon has also made inroads with Kindle in other Asian markets, bringing its e-reader to India in September and to Japan in October.