COPENHAGEN—Vestas Wind Systems A/S said Thursday it will shed more than 2,300 jobs, or 10% of its work force, close one of its 26 factories and reshuffle management in a cost-cutting plan as it grapples with industry overcapacity.

The world's largest wind-turbine manufacturer also warned that if U.S. lawmakers fail to extend a renewable-energy subsidy, known as the production tax credit, which expires by the end of 2012, it could lead to the layoff of an additional 1,600 workers in the U.S. Vestas will start preparing for...