A large chemical shipping company is being investigated by the Treasury Department for possible business dealings with certain countries, such as Iran, that are subject to U.S. embargoes.

"We are cooperating with them,'' said Richard Lemanski, a spokesman for Stolt-Nielsen Transportation Group Ltd. in Connecticut. "We provided information to the Treasury Department several months ago and have not heard back since,'' Lemanski said.

Treasury's Office of Foreign Assets Control helps enforce sanctions against terrorists, drug dealers and foreign countries — such as Cuba, Iran, Iraq and North Korea — that the United States doesn't want companies doing business with.

Neither Treasury Department officials nor the company would comment on the status of the probe.

Stolt-Nielsen Transportation Group, a major shipper of petrochemicals, fats and oils, is a wholly owned subsidiary of Stolt-Nielsen S.A., which has a main office in London.

Earlier this year, Treasury said that dozens of companies had paid the government millions of dollars for alleged violations of embargoes against nations including Cuba, Iran and Iraq.