Sun Microsystems Inc warned that quarterly results will sharply miss Wall Street projections, but the news did not appear to faze Oracle Corp , which is buying the company for $7 billion.

Oracle, the world's No. 3 software maker, said on Tuesday that it had reviewed Sun's preliminary results and reiterated its expectation that the acquisition would add to profit in the first full year after the deal closes.

Still, Sun's warning to investors underscores concerns that Oracle faces an uphill battle in turning around the money-losing company, whose market share has been declining for years as it lost business to International Business Machines Corp , Hewlett-Packard Co and Dell Inc .

Sun, based in Santa Clara, California, projected revenue of $2.58 billion to $2.68 billion for its fiscal fourth quarter ended June 30, shy of analysts' view of $3.06 billion, according to Reuters Estimates. Sun posted revenue of $3.78 billion a year earlier.

Cowen & Co analyst Peter Goldmacher, who has a neutral recommendation on Oracle, said he had not expected Sun's revenue to fall as much. People continue to underestimate how poorly Sun ran its business. Its products are clearly out of favor with the market, he said.

Sun also estimated a net loss of 24 cents to 34 cents a share for the quarter, versus Wall Street's average forecast for a per-share loss of 8 cents, according to Reuters Estimates.

A spokeswoman for Sun declined to discuss the reason for the shortfall.

Oracle executives have said that it will take time to turn around Sun's ailing hardware division, though they do expect to make it profitable.

Oracle said on Tuesday it still expects the acquisition to add more than $1.5 billion to its operating profit before special items in the first full year after closing, and reiterated a projection that the deal will boost profit, excluding items, by at least 15 cents per share.

Analysts say Oracle can do that by slashing Sun's bloated cost structure while milking revenue from high-margin maintenance services on Sun's hardware and the Solaris operating system. Its top-selling products are high-end servers, which run on Solaris, and storage equipment.

Jefferies & Co analyst Ross MacMillan said he was not surprised by Sun's preliminary results because many Wall Street analysts who followed the company had stopped updating their estimates after the Oracle deal was announced in April.

The numbers were irrelevant, said MacMillan, who recommends buying Oracle's stock.

Sun was unchanged at $9.16 on Nasdaq at mid-afternoon. Oracle shares fell 0.6 percent to $20.59 versus a 0.1 percent increase in the Nasdaq composite index.

Oracle Chief Executive Larry Ellison has said that one of Sun's greatest assets is its Java software, among the world's most widely used computer languages. Companies that use it include Oracle rivals IBM and SAP AG .

Sun said it will post its full quarterly results in a filing with the U.S. Securities and Exchange Commission by August 31, but that it would not hold a conference call with analysts.

Redwood City, California-based Oracle has said it expects the acquisition to close by the end of next month, pending approval by antitrust regulators in the United States and Europe.

Sun will formally count shareholders' votes on the Oracle deal on Thursday.

(Reporting by Jim Finkle and Franklin Paul, editing by Gerald E. McCormick, Derek Caney and Richard Chang)