Joining a rapidly growing list of technology companies reeling from the financial turmoil, Sun Microsystems has started a restructuring in which up to 6,000 employees could lose their jobs.

Before the stock market opened Friday, Sun disclosed that it would lay off between 5,000 and 6,000 employees, or up to 18 percent of its work force. The company, already dealing with layoffs announced in May, expects to save $700 to $800 million a year as a result of the moves, while also taking up to $600 million in charges in the next 12 months.

In the last two weeks, several of the technology industry’s biggest names have issued dire forecasts.

Last week, Cisco Systems, the largest provider of network equipment, warned that sales in its current quarter could drop 10 percent. Intel, the world’s largest producer of chips used in PCs and servers, added to the gloom this week saying its sales for the current quarter could plummet as much as 19 percent as both consumer and corporate customers had pulled back on technology spending.