BRIGHTON - Wind-power company Vestas will abandon plans to consolidate its three U.S. research and development operations to one location in Brighton, the company announced Wednesday.

Denmark-based Vestas Wind Systems A/S had planned to combine R&D operations from Louisville, Houston and Marlborough, Massachusetts. Instead, it will shut down all three sites.

The maker of wind turbines has decided to further "simplify" its global research and development operations to cut costs, the company said. All three R&D offices in the United States will be shut down by the end of the second quarter of 2013, costing 85 people their jobs.

The company has laid of roughly 500 people in Colorado this year amid a market slowdown in the United States caused in part by uncertainty about whether Congress will renew a wind production tax credit. Altogether, Vestas will have laid off close to 4,000 people worldwide this year.

"This is a difficult decision to part with dedicated and talented people who contributed to Vestas' success," the company said in a statement.

Vestas also closed R&D locations this year in China, Denmark and Singapore, and reduced its R&D employee base by about 20 percent compared with 2011. Vestas will continue to have an R&D presence in six other locations around the world.

Vestas signed a six-year lease for its Louisville operations - 48,000 square feet of space on Centennial Parkway - in July 2010.

Congress adjourned until after the Nov. 6 election without renewing the wind-energy production tax credit. Set to expire at the end of the year, the credit supports thousands of Colorado jobs tied to wind-energy development projects.

U.S. Sen. Mark Udall, D- Colo., laid blame for Vestas' decision at the feet of Congress for failing to quickly extend the wind production tax credit earlier this year. Congress' failure to extend the PTC and provide the wind industry with the certainty it needs has resulted in hundreds of layoffs in Colorado and across the United States, he said.

"These layoffs are symptomatic of larger problems in Washington, where even bipartisan bills get politicized and stymied," Udall said. "The opponents of extending the PTC are treating our energy security - and ultimately our national security - as a political football. These layoffs are on their hands. Our nation needs to follow Colorado's example of pursuing an all-of-the-above energy portfolio that will create jobs and improve the environment. We can't put this off any longer."