Calix said Wednesday that fourth-quarter revenues and profits would not meet Wall Street expectations, becoming the second Petaluma networking equipment company this week to warn investors to brace for unexpected results.

Calix now projects fourth-quarter revenues in the range of $93.5 to $94.5 million, down from its Oct. 29 forecast of $97 to $103 million.

It forecast profits of 2 to 4 cents per share for the quarter, down from its previous forecast of 3 to 8 cents per share. The non-GAAP earnings figures exclude one-time costs and other charges which the company believes are not indicative of its core operating results.

Calix cited an unexpected drop in spending by its customers, who historically have funneled more year-end orders to the company in an annual "budget flush."

Last year, Calix reported $91.4 million and non-GAAP earnings of 6 cents per share in the fourth quarter.

The company, which will release its fourth-quarter results on Feb. 11, issued the warning after U.S. markets had closed. Its stock dropped more than 8 percent in after-hours trading, to $8.45 a share.

On Monday, Cyan lowered its year-end guidance for investors. Since then, its stock has tumbled 33 percent, closing Wednesday at $3.50 a share.