WASHINGTON — The American government is seeking information from Iran about a former FBI agent who was reported missing while on a business trip there several weeks ago.

FBI spokesman Rich Kolko said yesterday that the agent had retired nearly a decade ago and appeared to be in Iran on private business. He said the missing man was last seen there in early March and was not working for the FBI as a contractor.

“At this time, there are no indications that this matter should be viewed other than as a missing person case,” Mr. Kolko said.

Mr. Kolko also said the former agent had worked on traditional criminal issues such as organized crime cases — drawing a distinction between those and international terrorism or intelligence work that could have taken him to Iran.

State Department spokesman Sean McCormack said America saw no connection between the missing man and the current crisis between Iran and Britain over 15 British sailors and marines arrested last month by Iranian forces.

The department has sent a letter to the Iranians through diplomatic intermediaries, asking if authorities there have any information about the man, Mr. McCormack said.

He said the State Department had been in constant contact with the man’s family and his employers since he was reported missing, but the spokesman did not say why it had taken three weeks to get in touch with Iran about the case.

“It’s an American private citizen who is in Iran on private business about whom we are pursuing welfare and whereabouts [information],” Mr. McCormack told reporters. “We have been monitoring this situation for a couple of weeks now.”

The Bush administration has increased diplomatic and other pressure on Iran in recent months, including added naval power in the Persian Gulf, while also making new overtures. Secretary of State Rice is expected to sit down soon for international talks with Iran’s foreign minister over the violence in neighboring Iraq.