The international insurance firm ING Group may be in some serious hot water. ING is under investigation in the U.S. for violating United States sanctions against nations that support terrorism.

The U.S. has been imposing economic sanctions and strict exporting restrictions with Cuba, Iran, Sudan and Syria. The U.S. sanctions limit the amount of business American companies may conduct with the nations that are perceived to be too friendly with terrorist operations.

The fines would be far from chump change. Sources have reported that depending on the results of the U.S. investigations, ING could face penalties for hundreds of millions of dollars.

ING noted in its 2010 annual report that talks with the U.S. Office of Foreign Asset Control, Department of Justice and the New York County District Attorney's Office could amount to a mega-million-dollar fine.

In 2010 the British bank Barclays P.L.C. was slapped with a $298 million fine over violations relating to the U.S. trade sanctions with  Cuba, Iran, Libya, Sudan and Myanmar.

In addition, Credit Suisse Group A.G. , Lloyds Banking Group P.L.C. and ABN AMRO have forked out massive U.S. settlements ranging from $350 million and $538 million as a result of similar violations.

Based in the Netherlands, ING provides financial services products including annuities, employee benefits, life insurance, mutual funds, retirement plans, rollovers & transfers and trusts.