Network gear maker Juniper Networks Inc (JNPR.N) said its chief executive of five years, Kevin Johnson, will retire once a successor is named.
The company's shares fell as much as 6 percent in post-market trading.
Johnson, 52, who joined from Microsoft Corp (MSFT.O), has been CEO since September 2008.
The announcement caused some confusion and nervousness, Pacific Crest Securities analyst Brent Bracelin said.
Juniper also forecast current-quarter results largely above analyst estimates after reporting a better-than-expected second quarter as spending by telecom service providers recovers.
Verizon Communications Inc (VZ.N), one of Juniper's largest customers, reported better-than-estimated growth in its wireless business in second quarter last week and raised its capital spending budget.
Juniper expects current-quarter adjusted earnings of 29 cents to 32 cents per share on revenue of between $1.14 billion and $1.18 billion.
Analysts on average were expecting earnings of 29 cents on revenue of $1.14 billion, according to Thomson Reuters I/B/E/S.
Net income rose to $98 million, or 19 cents per share, in the second quarter, from $57.7 million, or 11 cents per share, a year earlier.
Revenue rose 7 percent to $1.15 billion.
Excluding items, the company earned 29 cents per share.
Analysts on average were expecting Juniper to earn 25 cents per share on revenue of $1.09 billion.
Network equipment makers such as Juniper, Riverbed Technology Inc RVBD.O and F5 Networks Inc (FFIV.O) were hit last year, as spending by U.S. telecom companies was sluggish due to a faltering U.S. recovery and weakness in Europe.
(Reporting by Neha Alawadhi and Lehar Maan in Bangalore; Editing by Ted Kerr and Sriraj Kalluvila)