* Q4 adj loss/shr, rev beats Street view
* Sees Q1 adj loss/shr $0.10-$0.11 vs est $-0.07
* Q1 sales forecast beats estimates
* CFO Williams to be replaced by Brennan
* Shares fall 3 pct after the bell
Jan 26 (Reuters) - Communications equipment maker Infinera Corp (INFN.O) posted a narrower-than-expected quarterly loss, and said that expenses related to a new product launch would hurt its first quarter.
"Operating expenses will increase in first quarter, primarily due to significant increases in research and development, and we believe that first quarter will be our peak expense level for 2010," Chief Financial Officer Duston Williams said on a conference call with analysts.
The company forecast a first-quarter loss of 10 cents to 11 cents a share, on revenue of $92 million to $94 million, compared with analysts expectations of a loss of 7 cents a share, excluding items, on revenue of $84.6 million, according to Thomson Reuters I/B/E/S.
"They guided to sequential growth in what has been historically a seasonally down quarter suggesting that the optical industry is in an early stages of recovery," Pacific Crest Securities analyst Brent Bracelin said.
Infinera, which competes with Alcatel-Lucent ALUA.PA ALU.N, Ciena Corp CIEN.O and Cisco Systems Inc (CSCO.O), also said Ita Brennan will take over as its CFO succeeding Duston Williams who will resign effective June 26.
Fourth-quarter net loss increased to $18.7 million, or 19 cents per share, from $6.7 million, or 7 cents per share, a year earlier.
Excluding items, the company posted a loss of 7 cents a share, on revenue of $90.2 million.
Analysts expected a loss of 8 cents a share, excluding exceptional items, on revenue of $87.9 million.
Infinera, which provides digital optical networking systems to telecom carriers, counts companies such as Cox Communications Inc, Deutsche Telekom AG (DTEGn.DE), Spain's Telefonica (TEF.MC), Level 3 Communications LVLT.O and Global Crossing Ltd GLBC.O among its customers.
Level 3 sales contributed 12 percent of company's GAAP revenue, it said on a conference call with analysts.
Shares of the Sunnyvale, California-based company fell three percent in trading after the bell, but recouped those losses to trade flat at $7.80, their Tuesday's closing on Nasdaq. (Reporting by Shrutika Verma in Bangalore; Editing by Savio D'Souza)