Deutsche Börse, the German stock exchange, said on Wednesday that its Clearstream unit was the object of a criminal investigation into potential violations of United States money laundering laws and sanctions against Iran.
The exchange said the unit was cooperating with an investigation by the office of Preet Bharara, the United States attorney for the Southern District of New York.
“The investigation is in a very early stage and our U.S. counsels are currently analyzing the situation,” Clearstream said in a statement on Wednesday. “Investigation is a search process in a criminal proceeding. It is not a prosecution. Clearstream is currently not subject to prosecution.”
Clearstream, based in Luxembourg, provides post-trading and settlement services, namely delivering cash and securities between trading parties. It settles more than 250,000 transactions a day.
Shares of Deutsche Börse fell on the news, ending the day down 2 percent, to 56.59 euros, or about $78.02.
In recent years, the Manhattan district attorney’s office and the Justice Department have both aggressively pursued banks and others that have facilitated transactions by Iran and other countries or groups facing sanctions in the United States.
Last year, the Lebanese Canadian Bank, a defunct Beirut bank, agreed to forfeit $102 million as part of a settlement of accusations by the Justice Department that it helped launder hundreds of millions of dollars tied to the militant group Hezbollah.
In 2012, the British bank HSBC agreed to pay $1.9 billion and entered into a so-called deferred prosecution agreement, in which it would avoid prosecution if it committed no further wrongdoing in the next five years.
American officials said the bank allowed hundreds of millions of dollars in transactions from countries facing United States sanctions from the mid-1990s to about 2006, including Iran and Libya. HSBC said at the time that its legal issues were the result of its lack of a centralized structure globally.
In 2009, the Lloyds Banking Group agreed to pay $350 million in fines and forfeiture to settle claims by the Manhattan district attorney and the Justice Department that allowed Iranian and other clients to access the American banking system by removing identifying information from wire transfer requests, a process known as “stripping.”
On Wednesday, Clearstream said Mr. Bharara’s office had recently issued a grand jury subpoena seeking data on any property belonging to Iran or its central bank that was possibly being held by Clearstream, as well as services or acts undertaken by the unit for Iran’s benefit.
Clearstream said it would comply with the laws of all relevant jurisdictions.
Reuters reported on Tuesday that the grand jury subpoena was issued in a separate civil lawsuit in New York related to the 1983 bombing of a military barracks in Beirut that killed 241 American servicemen.
That lawsuit, filed in 2010, is seeking billions of dollars from financial institutions that the family members of victims claim facilitated the flow of money between Iran and terrorist groups.
In January, Clearstream agreed to pay $152 million to settle civil claims by the Treasury Department that its United States account was used as a conduit to hold about $2.8 billion in securities for Iran’s central bank from December 2007 to June 2008.