Canadian e-reading service provider Kobo Inc said on Tuesday it closed a C$50 million ($53 million) investment round aimed at speeding up expansion and new product development.

Kobo, was spun off from Canadian retailer Indigo Books & Music in late 2009, said existing investors contributed C$13 million of the funding and an unnamed leading institutional investor kicked in the rest.

Kobo will use the new funding to continue its explosive growth internationally, Greg Twinney, Kobo's chief financial officer, said in a statement.

Kobo has made no secret of its plans to become a top-three player in the digital book market and its eReading app comes preloaded on Research in Motion's BlackBerry PlayBook and on Samsung's Galaxy Tab.

Kobo said last week that it plans to launch local content stores in Germany and Spain from May, followed by stores for France, Italy and the Netherlands in the summer that offer eBooks, newspapers and magazines.

Kobo competes against Inc's Kindle, Apple Inc's iBooks -- although Kobo also has an app available for the iPad -- and Barnes & Noble Inc's Nook device, among others.

The e-reading service said it has 3.2 million users, with over 1 million added in the past 90 days.

Kobo is backed by majority shareholder Indigo, China's Cheung Kong Holdings, and institutional investors.

(Reporting by John McCrank; editing by Janet Guttsman)