Gigamon Inc (GIMO.N), which makes network traffic management software, estimated lower-than-expected first-quarter revenue, blaming cancellation of a large contract and delays in closing some contracts.
The company's shares fell as much as 21 percent in trading after the bell on Monday.
Gigamon forecast revenue of between $31 million and $31.5 million, below analysts' average expectation of $34.8 million, according to Thomson Reuters I/B/E/S.
The company previously forecast revenue of $34.0 million-$35.0 million.
Santa Clara, California-based Gigamon said it took a $2.3 million inventory charge related to cancellation of the EMEA contract.
The company will report first-quarter results on April 24 after market closes.
Gigamon's shares closed at $26.20 on the New York Stock Exchange.
(Reporting By Lehar Maan in Bangalore; Editing by Sriraj Kalluvila)