MINNEAPOLIS (AP) - The Minnesota Court of Appeals says an environmental impact statement should have been completed on the proposed Sandpiper pipeline before regulators granted the project a certificate of need.

The appeals court reversed the Minnesota Public Utility Commission's decision to grant that certificate, and sent the issue back to the agency to complete the environmental study before a new certificate is issued.

Minnesota regulators said in June that the 610-mile pipeline from North Dakota's Bakken oil fields to Superior, Wisconsin, is necessary. An environmental review was set to take place as Enbridge Energy determined the pipeline's final route.

But the appeals court says the certificate of need constitutes a major governmental action, so under state law, the environmental impact statement must be completed before it is granted.