* More than 20,000 workers join protests - union
* Rallies at about 30 sites across Germany
* Union says protests are a "warning shot"
* EADS to detail restructuring plans on Dec. 9
More than 20,000 workers from EADS in Germany took to the streets on Thursday to protest against the European aerospace company's restructuring plans which they fear could cost thousands of jobs.
EADS, part-owned by the French and German governments, is planning to combine its defence and space subsidiaries next year and has said it might sell off some units.
The company is due to announce details of the shake-up on Dec. 9, but industry sources have said the plans could cost several thousand jobs.
The protests spanned about 30 EADS sites in Germany, including EADS-owned airplane maker Airbus's factories in Finkenwerder and Stade near Hamburg and Airbus supplier Aerotec in the Bavarian city of Augsburg, according to Germany's IG Metall labour union.
"This is a warning shot, so that management knows that we will fight if it wants to make cuts," a spokesman for IG Metall said.
EADS employs about 140,000 in total worldwide, of which there are about 50,000 staff in Germany.
"What is happening here is just not right," said Peter Stoerecker, a worker at EADS's site in the Bavarian town of Manching, where about 1,000 workers marched through snow.
Protesting workers blew on red plastic whistles as they marched and were accompanied by a brass band with trumpets, tubas and trombones.
"We make a profit, we are working at full capacity," Stoerecker said.
The Manching site is seen at particular risk in the restructuring as it depends on future orders for the Eurofighter jet at a time when national governments are reigning in their defence budgets.
A spokesman for EADS in Germany said: "This is about securing the company's ability to compete in the defence and space business in the long run, but significant cuts are necessary to achieve that."
The shake-up at EADS aims to provide greater cohesion to disparate defence activities and comes a year after Chief Executive Tom Enders had to bow to political opposition to his attempt to merge with UK arms firm BAE Systems.
The company wants to streamline a collection of German, French and Spanish businesses that created EADS in 2000, as part of plans to double margins to 10 percent by mid-decade and get a global lift from one of Europe's best-known brands, Airbus.
The reorganisation follows EADS decision earlier this year to scrap a decades-old Franco-German ownership pact, putting a limit on government interference and giving its management more freedom to reshape the company.