Shares of Juniper Networks plunged nearly 11 percent as the Internet equipment maker reported dismal fourth-quarter results and it lost market share to No. 1 maker Cisco Systems.

Juniper shares fell 8 percent, in early Friday trading but recovered to close at $21.69, down 3 percent, giving the Sunnyvale, Calif.-based company a market value of $11.4 billion. Before the market opened, they had fallen about 11 percent.

Juniper has had problems with earnings and maintaining its approximately 20 percent market share in the burgeoning market. Cisco Systems has more than 50 percent share. Both are major shippers of switches, hubs and routers that maintain Internet traffic.

Juniper said fourth-quarter net income plunged 50 percent to only $96.2 million, or 18 cents a share, as revenue dipped to only $1.12 billion.

Moreover, CEO Kevin Johnson issued a lackluster first-quarter forecast for earnings ranging between 11 cents and 14 cents a share, versus analyst expectations of 27 cents.

Analyst George Notter of Jefferies said Juniper Networks may be feeling the effects of lower capital investment this quarter by major customers AT&T and Verizon Communications. The guidance for the quarter reflects a very healthy dose of conservatism that may be not fully appreciated by investors.

As a result, he maintained a buy rating on the shares, which he estimated could recover to $27.50.