A weak market for wind turbines in the U.S. will slow job growth at Vestas Wind Systems' four Colorado plants, Ditlev Engel, the company's chief executive, said Tuesday.

"When the world's biggest market takes a breather for a year, it's tough," Engel said in a telephone interview.

Vestas, the world's largest wind-turbine manufacturer, is investing $1 billion in four Colorado plants.

The Windsor facility is already manufacturing blades. The Pueblo plant recently completed its first tower, and two plants in Brighton are set to open in 2010, Engel said.

The plants are slated to create about 2,500 new jobs, according to the company.

In the company's third-quarter results, released Tuesday, Vestas said, "Due to the credit crisis, the upgrading in the USA is not progressing as quickly as planned."

The credit crunch and the recession stalled many wind-turbine projects, said John Hardy, an analyst with Broadpoint AmTech.

"Wind-farm projects are capital-intensive and require financing. There just wasn't any," Hardy said.

The slowdown in hiring is a way for the company to manage costs, Hardy said.

Vestas also is facing stiff competition from GE Energy and Siemens USA, Hardy said.

"At the moment, the U.S. market is characterized by excess capacity, which results in non-attractive prices and conditions on certain projects," Vestas said in its earnings report.

"The upgrading of the staff at the new factories in the USA will consequently take place in line with the order intake," the company said.

"We are going to get to 2,500 jobs; it is just a question of how quickly," Engel said.

Engel said the company is expecting prices and conditions in 2010 to be similar to this year.

"We are expecting a recovery," he said. ". . . The question is timing."

The Colorado plants remain a key to Vestas competitively, Engel said.

The U.S. manufacturing facilities will help reduce currency-fluctuation risk that Vestas faced when importing turbines.

"Without the U.S. facilities, we'd be at a disadvantage," Engel said.

Vestas reported third-quarter earnings of $246 million, up 70 percent compared with the third quarter of 2008.

Sales were up 3.1 percent to $2.7 billion.

In the wind-turbine business, quarterly earnings can vary because of the way projects are booked, Hardy said.

"Six months is usually a better measure, but considering this year, this is a good result," he said.