TORONTO -- Kobo Inc. says its e-reader customer base grew by 2.5 million in the first quarter despite weak predictions for the digital book industry.

The Toronto-based, Japanese-owned e-reader company says it now has 14.5 million registered users, with 15 per cent of its new users coming from the United States.

Kobo's customers were also reading 34 per cent more in the first quarter compared with the same time period last year.

Sales of the new Kobo Aura HD accounted for more than one in four eReaders sold at retail stores and sales of Kobo Writing Life self-publishing titles made up 10 per cent of revenue.

The company didn't disclose its revenue.

Kobo was founded by Toronto's Indigo Books & Music Inc. (TSX:IDG), which sold its remaining share of the ebook company last year to Japan's Rakuten Inc. in a deal worth US$315 million.

It has been working to rival competitors such as Amazon's Kindle, Barnes & Noble's Nook and the Apple iPad by expanding its presence internationally, including the U.S.

It also expects its growing library with books like Dan Brown's "Inferno" and Khaled Hosseini's "And the Mountains Echoed," will continue to grow its customer base as it expands to India, China and Russia.