UPDATE 4-GM's U-turn on Opel sale angers Germany, Russia

* German Economy Minister says GM behaviour "unacceptable"

* Russia's Putin says GM should not have final word

* Opel labour leader rescinds cost-cut contributions

* Opel to implement GM board decision quickly

(Adds comments from EU, Britain, Opel workers)

By Angelika Gruber and Gernot Heller

FRANKFURT/BERLIN, Nov 4 (Reuters) - German and Russian leaders seethed and unions tore up a deal to cut costs in protest at General Motors' [GM.UL] "completely unacceptable" decision to keep Opel, its European unit, after months of talks.

Labour leader Klaus Franz rescinded hundreds of millions of euros in cost concessions that workers agreed to on condition that Opel was bought by Magna (MGa.TO), the Russian-backed Canadian group long backed as buyer by Berlin and Moscow.

"General Motors' behaviour towards workers is completely unacceptable," German Economy Minister Rainer Bruederle told reporters the morning after GM's shock news, adding: "General Motors' behaviour towards Germany is completely unacceptable."

In Moscow, Russian Prime Minister Vladimir Putin hinted the battle for carmaker Opel was not over, saying it was the German trust overseeing Opel, not the board of General Motors, which should decide any further steps. [ID:nL4159263]

Germany viewed Magna and Russian partner Sberbank (SBER03.MM) as most likely to preserve as many German jobs and plants as possible. Half of Opel's 50,000 staff are based in Germany.

"General Motors' behaviour shows the ugly face of turbo-capitalism," said Juergen Ruettgers, premier of the state of North Rhine-Westphalia, home to an Opel plant in Bochum which is seen at risk of closure.

GM Europe will now revert to a reorganisation plan that envisages chopping fixed costs at Opel by 30 percent, a spokeswoman said.

"Failure to reach the needed restructuring would result in the operation becoming insolvent, an unnecessary and undesirable outcome for all involved," GM Europe said.

The spokeswoman declined to discuss potential job losses and plant closures, but German staff feared the worst.

NEW DEAL