Network computer maker Sun Microsystems Inc. revised its financial outlook on Tuesday, cutting its sales forecast for its fiscal fourth quarter to 10 percent or more below Wall Street expectations.

Sun estimated in a statement that its sales would be $3.8 billion to $4.0 billion. That compared to a consensus estimate of $4.4 billion from analysts polled by tracking firm Thomson Financial/First Call. 

Sun, which in the past has blamed economic weakness for slower sales but on Tuesday gave no reason for the revisions, estimated that its per-share earnings for the fiscal fourth quarter would be 2 to 4 cents. Analysts polled by First Call had a consensus forecast of 6 cents for the quarter, which ends in June. 

Shares of the company lost $1.80, or 8.8 percent, closing at $18.67 on the Nasdaq before Sun released the statement. 

Sun, which will host an earnings conference call later on Tuesday, took the number one U.S. server sales spot from International Business Machines Corp. last year, but analysts say it faces tough competition from that company and others. 

Revenue growth had accelerated to 60 percent in the first quarter of this fiscal year before the economic weakness hit the company. 

Sun had predicted in April that sales for its fourth quarter would be up slightly from the third quarter's $4.1 billion and that pro forma earnings per share would be flat or slightly down from the third quarter's 8 cents per share.