Thompson sells $38,000 in company stock with Iran ties - WKOW 27: Madison, WI Breaking News, Weather and Sports

MILWAUKEE (WKOW) -- Republican U.S. Senate candidate Tommy Thompson sold stock in four companies worth $38,000 after learning they have ties to Iran, according to his campaign.

Thompson first talked about the stock sale on Thursday, when it came up during his second debate with Democratic challenger Tammy Baldwin. Then, Thompson said he had been unaware that his stock broker had purchased shares in those companies and that he sold them when he found out.

Campaign spokeswoman Lisa Boothe said the companies included Royal Dutch Shell and Schlumberger.

The $38,000 represents only a small amount of Thompson's wealth. He's told the Milwaukee Journal Sentinel he has at least $13 million in assets and more than $5 million in income since the start of 2010.