Halliburton said all of the commitments of its subsidiary doing business in Iran have been completed and it is no longer working in the country.
In January 2005, the company once headed by U.S. Vice President Dick Cheney announced it would not accept new work in Iran but would complete its existing contracts there.
The U.S. Department of Justice subpoenaed documents from Halliburton in July 2004 for an investigation into the legality of contracts its Cayman Islands-registered Halliburton Products & Services Ltd unit held for work with the state-run National Iranian Oil Company.
U.S. companies are forbidden under U.S. law from doing business in Iran dating back to sanctions imposed after the 1979 Islamic revolution when student fundamentalists held 52 American hostages for 444 days.
Halliburton has said its operations in Iran, handled through a Dubai office, were legal because they were isolated from the U.S. operations and management.
"Halliburton's prior business in Iran was clearly permissible under applicable laws and regulations," the company reiterated in the statement today.
Last month, Halliburton announced its Chief Executive Dave Lesar would move to Dubai from Houston to open a new headquarters there to better position itself to win Middle East contracts.
Cheney was chief executive of Halliburton from 1995 to 2000 before becoming President George Bush's running mate.