Del. Code tit. 26, § 214

The Commission may make joint investigations, hold joint hearings within or without this State, and issue joint or concurrent orders in conjunction with any official, board, commission or agency of any state or of the United States. Whether in the holding of such investigations or hearings, or in the making of such orders, the Commission shall function under agreements or compacts between states or under the concurrent powers of states to regulate the interstate commerce, or as an agency of the federal government, or otherwise.