UPDATE 1-FireEye forecasts loss for fourth quarter, shares tumble

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Nov 1 (Reuters) - Cybersecurity firm FireEye Inc said on Wednesday it was likely to post a loss for the fourth quarter of 2017, disappointing investors who were promised an adjusted profit by the end of the year.

Shares of the company were down 10.2 percent in aftermarket trading on Wednesday.

FireEye, which has investigated some of the biggest cyber attacks to date including the Equifax breach disclosed in September, is yet to report a profit since going public in 2013.

It expects its fourth-quarter bottom line, on an adjusted basis, to range between breakeven and a loss of 3 cents per share.

Analysts on average were expecting a loss of 1 cent per share, according to Thomson Reuters I/B/E/S.

The forecast was accompanied by stronger than expected results for the third quarter, with net loss attributable to shareholders narrowing to $72.9 million, or 41 cents per share from $123.4 million, or 75 cents per share, a year earlier.

"It's been a bumpy road for FireEye over the past few years but it appears they are directionally heading in the right direction even though the bulls were hoping for more around the company's outlook," GBH Insights analyst Daniel Ives told Reuters.

The Milpitas, California-based company expects revenue of $190 million to $196 million for the final quarter of 2017, compared to analysts' estimate of $195.9 million.

Asked by Reuters about the positive impact of its response to the Equifax breach on product sales, CEO Kevin Mandia said: "I haven't seen any direct impact of that breach, other than, just additional awareness that the liabilities are significant."

FireEye said total revenue rose 1.7 percent to $189.6 million in the quarter ended Sept. 30. (Editing by Savio D'Souza and Patrick Graham)