Associated Press

IOWA CITY, Ia. — The Iowa Utilities Board has dealt another setback to a proposed $2 billion transmission line to ship Iowa wind energy to customers in Illinois.

The board voted 3-0 on Monday rejected the third request by Clean Line Energy Partners to split the case into two separate hearings. The board stood by its plan to decide whether to approve the line and whether to grant the use of eminent domain in one hearing.

The company has said that approach means it has to invest "tens of millions of dollars" acquiring land while running the risk that regulators could reject the line as not in the public interest.

Groups representing union workers and wind energy supporters backed its latest request to split up the case,saying they were not interested in the property rights issues and only on the need for the line.

The board said Clean Line Energy cleared up some concerns it had about adversely impacting "the bargaining position of the affected landowners." The company said it would not change its calculations for easements even with eminent domain powers.

But the board said it still remained concerned landowners would bear additional costs for lawyers with two hearings.

The board is the last regulatory agency needed to sign off on the line, which the company says would produce enough electricity to power 1.4 million homes in the Midwest. But many Iowa landowners say the company isn't offering enough compensation to build on their property and should not be granted eminent domain.

The line would start in northwest Iowa and ship power produced by wind turbines 500 miles to a converter station near Chicago.

The company has only obtained voluntary agreements with about 15 percent of the affected property owners and has put on hold plans to obtain access to more land as it works through the procedural issues.

Clean Line Energy's Beth Conley said the company is reviewing the order and evaluating its next steps.

Illinois and the federal government have given their approval to the project.

— The Register's Donnelle Eller contributed to this report.