SPARK Ventures' part-owned mobile communications services provider IMImobile(IMI) floated on the AIM market on the London Stock Exchange on Friday.IMI raised £30m before expenses through the issue of 25m shares at 120p each.Early-stage venture capital company SPARK sold around a fifth of its holding in the initial public offering (IPO) to raise aggregate net proceeds of approximately £3.2m, SPARK's remaining 17% interest in IMI has a value of around £12.9m at the IPO price.IMI remains SPARK's largest investment holding.The company's recent published financial reporting date showed it held 27% of the issued share capital of IMI which was valued at £14.8m on September 2013.As of 10:50 SPARK's share price was unchanged at 5p.WS