The cuts will be mainly in China, the US and Europe, totalling around 1,800. Spain is likely to take the brunt of the European job losses with 500 redundancies.
The annoucement's were made as part of new executive chairman Ignacio Martin's 2013-15 strategy for the company. Martin replaced previous CEO Jorge Calvet in May.
Overall, it said it was looking to reduce costs. This will include looking at fixed and variable costs, with the later likely to focus on the company's procurement strategy.
The company also appears to be applying the brakes to its offshore product development. Although Gamesa hopes to bring out a prototype 5.5MW offshore turbine next year this may go back to 2014. While the 7MW offshore turbine, which will be a separate platform and was supposed to be prototyped in 2014, is put back to the "medium to long term".
In a statement, Gamesa said: "Gamesa is undertaking a worldwide rationalisation process to adapt to the slowdown in demand and to attain an efficient operating model that guarantees a competitive level of fixed costs.
"The process, which commenced early in 2012, includes an overall reduction in the workforce between October and the first quarter of 2013 of around 1,800 jobs (20.2% of the worldwide total), both structural and operational, mainly in Europe, China and the US. At the end of the process, the company will have a global headcount of 6,200-6,300."
The company has been making job cuts throughout the year, primarily in Spain and the US. In Spain, this process began under Calvet who said he would make drastic cuts to Gamesa's Spanish operation unless the country's 2012 moratorium on new projects alters.
In Spain there were fears the upcoming cuts would be worse, with unions predicting as many as 1000. Speaking to Windpower Monthly last week, Clara Fernandez of manufacturing workers trade union CCOO declared: "we know with certainty layoffs will be extensive."
In August, Gamesa's announcement last month of 165 layoffs at two factories in Pennsylvania.
Gamesa said it expects to sell 1.8GW to 2GW in 2013 and 2.2GW to 2.4GW in 2015. This will include a shift towards emerging markets, particularly Latin America. The company also said it was looking to increase its O&M capabilities.