Sources says Force10 Networks Inc. 's latest funding round consists of $50 million in two tranches -- the first, already completed, for $35 million and the second, to be completed late September, for another $15 million. Separately, another source notes Force10 was out raising $35 million sometime in June.

The round sets Force10's post-funding valuation at $455 million, according to one source; other sources familiar with the company say that figure sounds about right.

With revenues likely to exceed $100 million this year, Force10 was all set for a 2006 IPO. It had even picked bankers including, reportedly, Morgan Stanley . But sources say the bugaboo of Sarbanes-Oxley compliance stalled the IPO's progress and, according to one, led Force10's CFO to depart earlier this year. (See Force10 IPO Still Hanging and Force10 Names CFO.)

Having raised at least $300 million in funding, and with revenues doubling each year, Force10 appears unlikely as an acquisition target. Officials have confirmed that an IPO is still in the plans -- although they won't discuss reasons for the delay.

With more than 200 employees, Force10 certainly is burning through cash -- but at a decelerated rate, thanks to hiring in India. The company's monthly burn rate is down to $4 million, according to one source.

Force10 officials did not immediately return calls for comment.

— Craig Matsumoto, Senior Editor, Light Reading