Wilson said at a briefing in Whitehall on Tuesday: "There is no question of the government cutting a deal [with the US] for contractors on the basis of Britain's military involvement."
He added, however, that the government expected British firms to be involved in the rebuilding of infrastructure and water systems.
Wilson said: "British firms will need to make a contribution to the reconstruction of Iraq on humanitarian grounds, including the provision of a water system and other infrastructure."
The minister emphasised the point that decisions about awarding contracts would be made on purely commercial grounds.
Wilson said the government expected UK firms to win work through normal commercial channels, such as Trade Partners UK and the UN.
The contractors have tongues in their heads – I’m sure they will be putting their cases forward
Wilson rejected claims that the government had failed to lobby effectively to secure rebuilding contracts for British firms.
He told Building: "The contractors also have tongues in their heads – I'm sure they will also be putting forward their cases for contracts."
Wilson said that he was aware of the difficult environment that British firms would encounter after the war, but added that they were well equipped to deal with the situation. He said that the companies could also seek advice from the Foreign Office on the issue.
Wilson's warning came as Carillion chief executive John McDonough said that the contractor would consider working in Iraq if the right opportunities arose.
In an interview in this week's Building, McDonough said he would carry out a "country sign-off", which would involve an internal evaluation by the executive board of the risks involved in working in Iraq. He said: "My number one priority is to ensure the safety of my staff."