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 centre 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: