Sun Microsystems Inc , the computer server maker being acquired by Oracle Corp , issued a revenue forecast that fell short of Wall Street estimates.

The forecast underscores concerns that it will be tough for Oracle to turn around the money-losing maker of computer servers, which has been declining for years as it has lost business to IBM , Hewlett-Packard Co and Dell Inc .

Sun, which also forecast a net loss, said on Tuesday it expects to report revenue in the range of $2.58 billion to $2.68 billion for the fourth quarter ended June 30 -- shy of analysts' view of $3.058 billion, according to Reuters Estimates. Sun posted revenue of $3.78 billion for the fourth quarter of fiscal 2008.

Sun expects a net loss per share for the fourth quarter in the range of 24 to 34 cents a share. Excluding special items, it sees a loss of 6 to 16 cents a share.

Separately, Oracle said the Sun acquisition is expected to add to Oracle's earnings before special items by at least 15 cents a share in the first full year after the deal closes. In all, the acquisition is seen adding over $1.5 billion to Oracle's operating profit.

Sun's Java software is one of the world's most widely used computer languages. Oracle CEO Larry Ellison has said he wants to tweak Java software so that it is easier to use on smartphones and netbook computers.

Shares of Sun were narrowly lower on trading before the opening bell on Nasdaq, slipping to $9.13 from Monday's close of $9.16. Oracle were up 3 cents to $20.75.

(Reporting by Franklin Paul, editing by Gerald E. McCormick and Derek Caney)