Shares of Casa Systems Inc. (CASA - Get Report) were cratering after the company issued a much weaker-than-expected forecast for its fourth quarter and the stock was downgraded by analysts at two firms.

The stock fell 22% to $11.20 a share. 

Casa issued preliminary guidance for its fourth quarter saying it expects revenue of between $63 million and $69 million, well under analysts' expectations of $100 million. The company expects earnings per share of between 13 and 17 cents, below estimates of 20 cents. The company expects gross margins to come in at between 70% and 73%. 

The lowered revenue guidance is largely attributable to a change in customer preference.

"Our fourth quarter results were impacted by lower than expected spending in hardware by certain MSO customers as they begin to transition from Integrated CCAP to Distributed Access Architecture (DAA)," said Jerry Guo, president and CEO of Casa Systems.

Production delays also caused management to delay the recognition of some revenue for the quarter. "To a lesser extent we also experienced wireless product certification delays, which has affected the timing of our wireless revenue recognition,"  Guo said. 

Analysts at both Stifel Nicolaus and Morgan Stanley downgraded shares of Casa Systems, a communications equipment company. Stifel downgraded the stock to hold from buy and lowered its price target to $14 a share from $18. Morgan Stanley downgraded the stock to equal weight from overweight, and lowered its price target to $11 a share from $18.