Microsoft has announced that it will cut up to 5,000 jobs over the next 18 months after it posted profit of $4.17bn for three months to December 31, 2008, down 11%.

Departments hit by the job cuts would be research and development, marketing, sales, finance, legal, human resources and information technology. A total of 1,400 workers will lose their jobs immediately, the company said.

The job cuts are part of a wider cost-cutting strategy, which the company hopes will reduce costs by $1.5bn.

Microsoft’s financial results were hit by the slowing PC market, with client revenue dropping 8% during the quarter.

Microsoft chief executive Steve Ballmer said: “While we’re not immune to the effects of the economy, I am confident in the strength of our product portfolio and soundness of our approach.”

“We will continue to manage expenses and invest in long-term opportunities to deliver value to customers and shareholders, and we will emerge an even stronger industry leader than we are today.”