Spotify becomes world's 'richest start-up' with $4 bn valuation

Online music-streaming service Spotify has reportedly raised 250 million dollars in a new funding round, making it one of the world's most richly capitalized start-ups valuing it at more than four billion dollars.

The extra funds can help the Swedish music service bolster its U.S. business, as its net losses increased to 77 million dollars in 2012, Mashable reports.

Spotify reportedly doubled its revenues in 2012 to nearly 600 million dollars with its growing popularity, but it continues to loose money by incurring losses.

Spotify previously raised 100 million dollars, almost exactly a year ago, with a 3 billion dollars valuation, the report added.