Online music streaming service Spotify's revenues leapt 45% to top €1 billion last year, though its operating loss widened due to product development and expansion costs, its holding company said.

Stockholm-based Spotify, which provides free on-demand music or ad-free tunes for paying customers, posted an operating loss of €165m, compared with a loss of €91m in 2013.

The company, founded in 2006 by Daniel Ek and Martin Lorentzon, was reportedly valued at about $8 billion in a recent fundraising.

It said the increased loss was due to substantial investments in product development and international expansion, as well as an increase in staffing.

Its sales grew to €1.08 billion in 2014 from €747m a year earlier.

The 2014 figures for its holding company Spotify Technology were obtained by Reuters from the Luxembourg company registry.