FACTBOX: Opel's sites and staff

(Reuters) - The board of General Motors has opted to keep Opel, undoing months of painstaking negotiations to sell the European unit to a Russian-backed group led by Canada's Magna. Countries with Opel plants had fought to save jobs -- 10,500 cuts were originally planned -- and avoid plant closures amid promises of billions in state aid.

Below is a summary of the main GM factories in Europe:

* GERMANY: GM employs around 25,100 people in Germany

RUESSELSHEIM: 15,600 employees assembled 120,000 vehicles last year at Opel's headquarters. The factory built the Vectra and Signum models as well as the new Insignia. The site also houses a technical center that carries out research and development for the GM group.

BOCHUM: 5,200 workers produced close to 200,000 Astra compacts and Astra-based Zafira vans last year. Under the original Magna plan, some 2,200 jobs were at risk, according to politicians.

EISENACH: 1,800 workers assembled 157,000 three-door Corsa subcompacts at the plant inaugurated in 1992 as a landmark project to revive eastern Germany's industrial structure.

KAISERSLAUTERN: 3,500 employees manufacture four-cylinder petrol and diesel engines and components. Close to 150,000 engines were built there last year.

* BRITAIN:

GM has 5,500 staff at Ellesmere Port and Luton. The Unite trade union said on October 13 it agreed a deal to secure the future of the two plants, saving 600 jobs and securing a promise that any redundancies would be voluntary.

ELLESMERE PORT: Ellesmere Port assembled 111,600 Astras and Astravans in 2008 under the Vauxhall badge, the British version of the Opel brand.

LUTON: Last year built more than 60,000 Vivaro delivery vans, a larger sister to the Combo used for commercial purposes. The site is also home to production of 27,000 Renault Trafic vans.

* BELGIUM:

ANTWERP: 133,000 Astras were built last year in a plant often said to be a leading candidate for closure. Belgian regional premier Kris Peeters told European Competition Commissioner Neelie Kroes last month that closing the site could not be justified on economic grounds. On October 15 unions agreed to 20.2 million euros of cost savings at the plant after Magna pledged to look into keeping the plant open.

* POLAND:

GLIWICE: 3,500 people built 170,000 vehicles last year, mainly Zafiras as well as Astras, making it a rival to Bochum for production volume.

* SPAIN:

ZARAGOZA: Built 423,000 vehicles in 2008, consisting of Corsas, the Meriva minivan based on the Corsa architecture and the Combo delivery van. On October 26, Spain's Opel workers voted to accept Magna's plans for the carmaker, after Magna had agreed to keep the Figueruelas plant in northern Spain and to reduce proposed job cuts. The plant employs 7,500 and Magna had proposed cutting 1,300-1,650 jobs.

Sources: Reuters/ here

(Reporting by Christiaan Hetzner; Writing by David Cutler, London Editorial Reference Unit; additional writing by Jijo Jacob, editing by Matthew Lewis)