Tech bellwether

Cisco Systems

(CSCO) - Get Report

was down 11.7% in preopen

Island

trading after

posting second-quarter earnings before items of 18 cents per share, below the

First Call/Thomson Financial

estimate of 19 cents. It was the first earnings miss for Cisco in three years.

Sales rose to $6.75 billion, short of the Street's estimate of $7 billion to $7.2 billion.

The network equipment maker also said growth would come to a halt in the next six months due to the slowing economy and curtailed technology spending.

Lehman Brothers

downgraded Cisco to buy from strong buy.

CNBC

said several other firms issued downgrades or cut estimates.

Other network companies were also lower.

Juniper

(JNPR) - Get Report

was down 5.6%.

Sycamore

(SCMR)

was down 4.2%.