The top executive at General Motors Corp said on Tuesday that the automaker was watching the downturn in the U.S. housing market closely and blamed the softness there for weakness in vehicle sales.

In an interview at the annual Frankfurt International Motor Show, Chief Executive Officer Rick Wagoner said the company was watching the situation carefully because the property market's woes were spilling over into auto showrooms.

It's created an environment where people are a little tense and when they get a little tense they hold onto their dollars and hold their cars a little longer, Wagoner said. So we saw reasonably weaker sales the last several months.

While insisting that many of the fundamentals in the United States look pretty good, Wagoner said the uncertainties had made the current period a tenuous one for the U.S. economy, the world's largest.

(Reporting by James B. Kelleher)