Amazon, the e-book market leader thus far has competition coming its way - with Sony announcing its plans to convert its electronic book store to the open EPUB format by the year-end!

EPUB is a standardized e-book format that can be read on a number of devices. The credit of developing the format goes to the International Digital Publishing Forum and a group of leading publishers - like Random House and Houghton Mifflin.

With the increasing adoption of the EPUB format, e-book owners would be able to shift their digital library from one device to another; similar to the way they shift CDs and DVDs.

Hence, the switchover of the Sony eBook store to an open format will give customers the opportunity to read a wide range of materials on the company's e-readers; thereby challenging Amazon which sells eBooks that can be read either on the Kindle e-reader or else the Kindle software on the Apple's iPhone.

Commenting on Sony's recent move, Steve Haber - head of Sony's digital reading business unit - said that Sony intends leading by example. Haber added: "A world of proprietary formats creates silos and limits overall market growth. With a common format and common content protection solution, users will be able to shop around for the content they want regardless of where they get it or whichever device they use."