Sun Microsystems has announced a sharp drop in sales for the June quarter as it prepares to put its planned acquisition by Oracle to a shareholder vote later this week.

In what may be its last results before being acquired by Oracle in a $7.4 billion deal, the server and software maker predicted a loss of 24 cents to 34 cents per share in the quarter ended June 30. Excluding one-time items, Sun expects a loss of six cents to 16 cents per share.

Revenue for the fourth fiscal quarter, ended June 30, is likely to be between $2.58 billion and $2.68 billion, down from $3.78 billion in the fourth quarter last year, Sun has said.

The loss is expected to be in the range of $0.06 to $0.16 per share, wider than the $0.03 per share that analysts had been expecting, according to CIO 100 ranked Thomson Reuters.

Sun is due to report its full results no later than August 31, the company said.

Oracle, which announced in April that it plans to buy Sun for $7.4 billion, said on Tuesday that it still expects the deal to add to its earnings in the first full year after closing.

Sun's shareholders are due to vote on the merger Thursday morning, at a special stockholder meeting in Santa Clara, California. The majority of Sun outstanding shareholders must be voted in favour of the deal for it to go ahead. The Sun board has recommended voting in favour of the agreement.

Sun stockholders would receive $9.50 in cash, before taxes, for each Sun share they own. Sun shares were trading at $9.17 late on Tuesday afternoon, up from $5.98 before the agreement with Oracle was announced.

Oracle CEO Larry Ellison has said wants Sun primarily for its software assets, but in a move to quell concerns among Sun customers he also pledged to continue the development of the Sun Sparc processor.

"Sun was very successful for a very long time selling computer systems based on the Sparc chip and the Solaris operating system," Ellison said in a May regulatory filing. "Now, with the added power of integrated Oracle software, we think they can be again."