Investors dumped Avici Systems ( AVCI) shares in premarket trading Friday after the Internet routing company warned about first-quarter revenue. Massachusetts-based Avici said revenue for the quarter ending March 31 will be $6 million to $8 million because of what it called "uneven customer order patterns," far below the consensus estimate of $10.8 million, according to Thomson One Analytics. Analysts also expect Avici to lose 72 cents a share during the period. Otherwise, Avici reaffirmed its full-year 2004 guidance, calling for 20% to 30% growth in revenue, which would total $44 million to $48 million, based on its 2003 performance. The consensus revenue forecast is for $48 million. The company reports quarterly earnings April 22. Shares fell $3.30, or 20%, to $13.13 before the opening bell.