Frankfurt, Germany - German carmaker Daimler will stop year-end production at two big German plants for four weeks, doubling the normal holiday stoppages given a sharp drop in demand, its works council said on Monday.

The Sindelfingen plant near Stuttgart that makes Mercedes-Benz C-, E- and S-Class models will shut down from Dec. 12 and reopen on Jan. 12, a works council spokeswoman said.

The Untertuerkheim motor and transmission plant will also halt most output from Dec. 15 to Jan. 12, a plant spokeswoman said.

Mercedes-Benz was not immediately available for comment.

On Sunday, Germany's Frankfurter Allgemeine Sonntagszeitung said the carmaker had imposed a five-week Christmas break for its 36,000 workers at Sindelfingen. Workers normally get only two to three weeks off during the holiday season.

The world's second-biggest premium carmaker last week lowered its full-year revenue and profit forecast after third-quarter operating profit plunged by two-thirds.

Daimler shares, which have already lost two-thirds of their value so far this year, were trading 12.1 percent lower at 19.69 euros at 1001 GMT, underperforming European auto shares and the broader German blue-chip index.

General Motors Corp'S European arm Opel, as well as BMW and Volkswagen units Seat and Skoda have said they plan to cut production as the financial crisis crimps consumer spending.

(Reporting by Marilyn Gerlach; Additional reporting by Hendrik Sackmann in Stuttgart; Editing by Quentin Bryar)