Sun Microsystems shares fell despite a quarterly profit reported overnight as revenue grew less than analysts had expected.
The company's stock, up 3.3 per cent this year on Friday, fell 2.5 per cent in extended trading after closing up 2 per cent at $5.71 on Nasdaq.
Fiscal first-quarter revenue rose less than 1 per cent to $3.22 billion, shy of the average forecast of $3.26 billion as compiled by Reuters Estimates.
Net income in the company's fiscal first quarter was $89 million, or 3 cents per share, compared with a net loss of $56 million, or 2 cents per share, in the year-earlier period. Net income included $113 million, or 3 cents per share, of restructuring charges.
Sun Micro, the third-largest maker of server computers for businesses, said its gross profit margin increased 5 percentage points to 48.5 per cent from the year-earlier period.