Warburg Pincus and IDG both bought 15 million shares for $5m each in RDA Microelectronics' series C round in January 2007 ahead of its planned Nasdaq flotation.

RDA Microelectronics, a China-based maker of communication chips, has filed for its $100m flotation on the Nasdaq stock exchange.

Since shipping its first chip in 2005, RDA posted $76m in revenue for the first six months of the year, compared to $46m for the first half of last year and full-year turnover of $118.4m.

RDA will list an undisclosed number of American Depository Shares worth an undisclosed number of common shares at its initial public offering (IPO), co-led by…