Borders Group Inc launched its long awaited electronic bookstore on Wednesday, along with applications for the store on several leading smartphones in a bid to catch up to rival booksellers and generate sales in the fast growing e-book segment.

Borders, the No. 2 U.S. bookstore chain by sales, said its new e-bookstore will allow customers to download books in several formats such as ePub, mobile technology and PDF.

The launch comes nine months after larger rival Barnes & Noble Inc launched its Nook e-reader, and three months after Apple Inc launched its iPad tablet computer, which has e-reader capabilities.

In addition to the applications recently launched for Apple's iPhone and iPad, Borders on Wednesday introduced applications for Research In Motion's Blackberry smartphones and phones with Google's Android software to allow the downloading of books on a wider array of devices.

Borders said that by the end of 2010, it would be selling a total of 10 different kinds of e-readers in stores and online.

Borders said its e-bookstore will offer 1.5 million titles, including free books. Amazon says it offers 620,000 books as well as 1.8 million free, out-of-copyright titles, and Barnes & Noble says it offers 1 million titles.

The e-bookstore launch comes at a time the struggling bookstore chain seeks to reverse a long slide in sales and win back book sales from Barnes & Noble, Amazon.com Inc and Apple, which were quicker to sell e-books and have large head starts on Borders in the e-books market.

A Goldman Sachs report in April forecast that e-booksales, which now make up 3 percent of overall U.S. book sales, would rise to 12.8 percent by 2015.

(Reporting by Phil Wahba; Editing by Muralikumar Anantharaman)