ATLANTA – Companies run by Republican presidential candidate Newt Gingrich have faced overdue tax bills in four states worth more than $6,000, according to records reviewed by The Associated Press.

The tax liens, which generally allow governments to seize assets or property to settle tax bills, ranged in size from a $195 property tax bill in the Atlanta suburbs to $1,969 in unpaid Missouri taxes. Most of the liens were paid shortly after tax authorities filed them.

One exception was in Pennsylvania, where Gingrich Holdings Inc. last week paid off a $1,599 lien for unpaid corporate income taxes just days before Gingrich formally announced he would run against President Obama, a Democrat.

Gingrich spokesman Rick Tyler said Gingrich and his businesses were unaware of most of the tax liens until being contacted last week by the AP. “When an issue has arisen, we’re anxious to resolve the issue and get the taxes paid,” Tyler said.

Georgia State University professor Jack Williams, who teaches multistate taxation, said he most commonly sees liens filed against firms in financial distress. Other contributing factors could be poor record-keeping or aggressive tax collectors.

“The lien stage is about as deep into the process you get before the taxing authority seizes your assets and sells that,” he said.

Until deciding to run for president, Gingrich was the CEO of Gingrich Holdings Inc., the parent company of firms that manage his book and TV contracts, produce documentary films, offer consulting services and oppose Obama’s health care overhaul. Tyler said Gingrich’s businesses are financially healthy.

Pennsylvania Department of Revenue spokeswoman Elizabeth Brassell, Missouri department spokesman Ted Farnen, and Indiana department spokeswoman Stephanie McFarland said privacy laws bar them from further discussing the cases in their respective states.