A group of states have reportedly jointed a federal anti-trust investigation into a joint venture agreement between Cargill, ConAgra Foods and CHS.

ConAgra Foods plans to join Horizon Milling, an existing joint venture between Cargill and CHS. The agreement would see the creation of a flour business – to be called Ardent Mills – that would control around one-third of the nation’s flour production.

According to a Reuters report, which cites two unnamed sources, a number of wheat-growing states are concerned Ardent would have the power to push down prices paid to farmers. The states, purportedly lead by the Oklahoma Attorney General, are apparently working to assist the Department of Justice investigation into the proposal.