Skype, an online phone operator started by entrepreneurs Niklas Zennstrom and Janus Friis, has invested in Rdio. Skype's investment came alongside one of its own original venture capital backers, Mangrove Capital Partners, which is a new investor in Rdio, and Zennstrom and Friis's new investment company Atomico.

Rdio, a US-based provider of online music, has raised $17.5m from Europe’s most influential investment diaspora.

Skype, an online phone operator started by entrepreneurs Niklas Zennstrom and Janus Friis, has invested in Rdio. Skype’s investment came alongside one of its own original venture capital backers, Mangrove Capital Partners, which is a new investor in Rdio, and Zennstrom and Friis’s new investment company Atomico.

Friis then went on from Skype to also found Rdio while Zennstrom reinvested in Skype after…