is teaming up with Microsoft to create an electronic bookstore, the two companies announced yesterday.

Although the companies wouldn't be drawn on exactly when the Amazon eBook store will appear, both parties said it will be "as soon as possible."

Amazon will offer Microsoft Reader as the "preferred format and preferred reading appliance" for its upcoming eBook store, according to Lyn Blake, general manager of Amazon Books.

Microsoft Reader is software that enables users to read electronic books, including a technology known as ClearType, designed to improve on-screen text resolution.

Visitors to the Amazon eBook site will be able to download a customised version of Microsoft Reader. "We chose Microsoft because it's the leading software technology for extended reading on any device," said Blake.

She wouldn't reveal any details on eBook pricing. "It's too early to tell," she said.

"We are partnering to bring eBooks to the masses," Dick Brass, Microsoft vice president of technology development, said.

He added that the customised version of Microsoft Reader for Amazon would be in the order of 90 to 99 percent similar to the standard release of the software, but couldn't comment on specific Amazon features.

Brass expects to see tens of thousands of titles available this year, with hundreds of thousands of eBook titles available a year from now.

Microsoft is currently working on improving the navigation features in its Reader software, Brass said.

One thing eBooks can't display that printed titles can is the sense of where a reader is in a book.

When you open a printed book to a particular page, you can see immediately, for instance, whether you're halfway through the book.

Microsoft is investigating how to duplicate that feeling in eBooks, he added.