Influential former Pentagon official Richard Perle has been exploring going into the oil business in Iraq and Kazakhstan, according to people with knowledge of the matter and documents outlining possible deals.

Mr. Perle, one of a group of security experts who began pushing the case for toppling Iraqi dictator Saddam Hussein about a decade ago, has been discussing a possible deal with officials of northern Iraq's Kurdistan regional government, including its Washington envoy, according to these people and the documents.