CORRECTED-UPDATE 2-Juniper's weak Q1 forecast stings shares

* Q4 adj EPS $0.28 vs est $0.28

* Q4 rev $1.12 bln vs est $1.13 bln

* Sees Q1 rev $960-$990 mln vs est $1.1 bln

* Sees Q1 adj shr $0.11-$0.14 vs est $0.26

* Shares down 8 pct in after-mkt trade

By Siddharth Cavale

Jan 26 (Reuters) - Juniper Networks Inc reported lower-than-expected quarterly revenue hurt by weak demand from service providers, and the network equipment maker forecast a first quarter well below analyst estimates, sending its shares down 8 percent after the bell.

"They (Juniper) continued to suffer from carrier capex, which is weak, and their end markets are becoming more competitive ... especially from HP," ThinkEquity Analyst Rajesh Ghai told Reuters.

The Sunnyvale, California-based company expects first-quarter adjusted earnings of 11 cents to 14 cents per share, on revenue of $960 million to $990 million.

Analysts, on an average, are expecting earnings of 26 cents a share on revenue of $1.1 billion, according to Thomson Reuters I/B/E/S.

Rival Riverbed Networks' shares also fell after the bell on a weaker-than-expected first quarter outlook.

Fourth-quarter net income fell to $96.2 million, or 18 cents a share, from $190.2 million, or 35 cents a share, a year ago.

Revenue fell 6 percent to $1.12 billion.

"They are losing share and that has been exacerbated by a soft quarter and you are starting to see that in the gross margins, and that is also evidence that competition has intensified," Mizuho Securities USA analyst Joanna Makris told Reuters.

Gross margins fell sequentially to 11.9 percent from 12.4 percent in the third quarter.

Juniper's shares, which closed at $22.37 on Thursday on the New York Stock Exchange, were down 8 percent to $20.55 in extended trade.