Tesla Motors is no longer taking orders for the sporty Tesla Roadster electric car in the United States, but will continue to sell the car in Europe and Asia until the third quarter next year.

“We’ve sold out of all custom orders for the roadsters, there are some spec cars available but otherwise we’re sold out,” Tesla Motors chief executive Elon Musk said on the company’s quarterly earnings call today. “You can’t actually buy a custom-ordered roadster in the U.S. any more.”

The company plans to ship the Model S in the United States initially. It will continue to sell Roadsters in other countries until it begins selling the Model S internationally, Musk said. There are still spec cars for sale that buyers can’t customize.

The car has proved popular because it’s a sporty model with one of the largest ranges for an electric car. It appeals to sports-car enthusiasts because it can go from 0 to 60 miles per hour in 3.7 seconds and has a top speed of 125 miles per hour. But it does carry a hefty price tag of $109,000. The company said it had sold 1,840 Roadsters by the end of its most recent operating quarter.

The electric-car maker is still working on its second car, the Model S sedan, which will be geared toward casual car buyers and those buying electric cars for the first time.  The Model S costs a slightly more reasonable $57,000 before government incentives for purchasing an electric car. The production model will come out in the United States around summer next year and in Europe toward the end of 2012.