By Lehar Maan and Richa Naidu
(Reuters) - Network security company FireEye Inc forecast current-quarter revenue below analysts' average expectation and warned that development costs would rise sharply, sending its shares down nearly 8 percent in after-hours trading.
FireEye, which acquired computer forensics specialist Mandiant Corp in January, said it expects revenue of $70-$72 million for the first quarter.
Analysts on average were expecting revenue of $76.2 million, according to Thomson Reuters I/B/E/S.
FireEye forecast current-quarter research and development costs to range between 50-53 percent of revenue. This implies expenses of between $35 million and $38.2 million, higher than the $21.5 million in the fourth quarter.
"Expenses are a little more than expected for the year... I think most investors here would focus on the growth profile, I think that's kind of splitting hairs in terms of expense shocks," FBR Capital Markets & Co analyst Daniel Ives said.
"They continue to under-promise and over-deliver. And that continues to be their sort of mantra," Ives added.
FireEye expects a loss of 51-56 cents per share for the quarter.
FireEye is focusing more on investment for future growth and is not looking at profitability in the near term, Chief Operating Officer Kevin Mandia told Reuters.
Mandia, founder of Mandiant, joined FireEye following its acquisition.
The company's revenue jumped 81 percent to $57.3 million in the fourth quarter ended December 31, slightly above analysts' average expectation of $56.1 million.
Governments and businesses have been beefing up their online security measures to safeguard data from threats posed by cybercriminals.
FireEye's adjusted net loss widened to $40.5 million, or 35 cents per share, for the fourth quarter ended December 31.
Analysts had expected a loss of 37 cents per share.
The company's shares were down 6.7 percent at $72.75 in extended trading after closing at $78.01 on the Nasdaq on Tuesday. The shares have nearly doubled in value since listing in September.
(Reporting By Lehar Maan and Richa Naidu in Bangalore; Editing by Sriraj Kalluvila)