Brian McCormack, Avici Systems Inc.'s (Nasdaq: AVCI; Frankfurt: BVC7) senior vice president of sales, has left the company, Light Reading has confirmed.

Avici has made no formal announcement of McCormack’s departure and says it doesn’t plan to. “We didn’t really view it as a material event,” says Esmeralda Swartz, Avici’s director of strategic marketing.

“Brian left on his own accord to pursue another opportunity,” says Swartz. Swartz also says that no replacement has been named “or talked about.”

McCormack, who has been traveling the past two days, left a message for Light Reading today confirming that he left Avici on his own and "under the best possible circumstances." Executive recruiters have told Light Reading they are now shopping McCormack's resumé to their clients.

The news highlights the pressure that comes with a sales position that requires selling against two giants, Cisco Systems Inc. (Nasdaq: CSCO) and Juniper Networks Inc.’s (Nasdaq: JNPR). In order to grow, Avici needs to carve out market share from either Juniper or Cisco in the core router market.

According to a recent report by The Dell'Oro Group, Avici shipped $8.8 million worth of WAN (wide area network) core routers in Q4 2000, compared to Cisco’s $540.7 million and $279.5 million.

For its most recent quarter, Avici beat Wall Street's expectations and raised its sales guidance for the year to $90 million from $70 million.

Prior to joining Avici, McCormack held a variety of positions with DSC Communications [now Alcatel SA (NYSE: ALA; Paris: CGEP:PA)]. Earlier, he was a regional manager for Cisco Systems Inc. (Nasdaq: CSCO) and a sales vice president at Nortel Networks Corp. (NYSE/Toronto: NT). He also worked at IBM Corp. (NYSE: IBM) for 12 years.

McCormack reported to Steve Kaufman, who just took on the dual role of president and chief operating officer in January. Kaufman joined Avici from Lucent Technologies Inc. (NYSE: LU) in July 2000 as COO (see Avici Adds to Management Team).

Now that McCormack has left, the folks that used to report to him -- Tony Casalena, vice president of North American sales and Russ Klabouch, vice president of international sales – now report to Kaufman.

Merrill Lynch analyst Sam Wilson says that McCormack’s departure is “probably not an earth shattering event,” noting that some senior defections are always expected when a company has been public for less than a year.

Avici debuted in the public markets in late July 2000 and once traded as high as 174.50. Avici shares closed at 15.12 yesterday and in early afternoon trading on Thursday, the stock had fallen 2.09 (13.8%) to 13.03, a new all-time low.

Wilson says that -- given Avici’s unprofitability, its high customer concentration, and the fact that all of its customers have equity stakes in the company -- there are reasons to be concerned about the challenges it faces.

-- Phil Harvey, senior editor, Light Reading http://www.lightreading.com