Readers for digital books are steadily becoming more popular
Sony is taking steps to open up its e-book Reader and online e-book store.
The electronics giant said it would stop using a proprietary standard in favour of the ePub open format.
Sony said it would have its store converted to the format by the end of 2009. Most Sony Readers can already handle books in the ePub format.
This may not mean the end of all locks on books readable on Sony's device as the ePub format has an option to implement copyright controls.
"Consumers should not have to worry about which device works with which store," said Steve Haber, president of Sony's digital reading business division, in a statement.
He added that the shift "allows Sony to make its e-book store compatible with multiple devices and its Reader devices open to multiple sources for content".
The common format would give Sony Reader owners much more choice about where they get their e-books from.
Many publishers are setting up their own e-book stores to help them promote the works of new authors and remind readers about the back catalogues of established writers.
Sony's move is also seen as a response to the widely perceived success of Amazon's Kindle e-book reader - although so far the online store has declined to reveal how many devices it has sold.
Sony and Amazon also face competition from the many other e-book reading devices that are starting to be produced. Currently there are about 20 dedicated e-book readers on sale or in development.
PCs and laptops can also display ePub e-books, as can high end phones such as Google Android devices and Apple's iPhone.
Partial figures gathered by the International Digital Publishing Forum suggest e-book sales are doing well. Wholesale e-book sales in the US jumped from $25.8m (£15.6m) to $37.6m (£22.7m) during the second quarter of 2009.
By contrast, sales at the end of the second quarter of 2008 stood at $11.6m (£7m).