Sun Micro Sparkles

Updated from 4:31 p.m. EDT

Sun Microsystems(SUNW Quote) sailed past analysts' profit expectations Monday, notching its third consecutive quarter in the black and sending its stock surging.

Additionally, the Santa Clara, Calif., computer company made good on a promise to the Street to bolster its operating profit margin.

Sun shares popped 50 cents, more than 10%, to $5.39 in extended trading Monday.

Sun's sales of $3.83 billion in its fiscal fourth quarter were flat year over year and in line with analysts' expectations.

But a slew of cost-cutting measures bought the company a profit of $329 million, or 9 cents a share vs. the average analyst expectation of 5 cents a share.

At this time last year, Sun had a net loss of $301 million, or 9 cents a share.

Sun boosted its gross profit margin by nearly three percentage points sequentially to 47%, thanks in part to lower prices for computer memory.

More symbolically, Sun said its operating margin in the recently ended quarter was 8.5%.

"With a solid strategy and consistent execution, we delivered on our commitment to achieve at least 4% operating margin in the fourth quarter. This milestone marks significant progress toward our long-term growth plan of at least 10% operating margin for the full fiscal year 2009," said Sun CEO Jonathan Schwartz.