The Federal Energy Regulatory Commission said it gave Wyoming Interstate Co., known as WIC, and Viking Gas Transmission Co. 75 days to hand over a full cost and revenue study. FERC said it opened the probe in order "to determine if they are over-recovering their costs, resulting in unjust and unreasonable rates for customers."
WIC, a Kinder Morgan company, operates about 800 miles of pipeline in Wyoming, Utah and Colorado with a design capacity of 3.34 billion cubic feet per day. Viking, owned by ONEOK Partners, transits natural gas from Canada through four pipelines servicing North Dakota, Minnesota and Wisconsin.
Neither company had a public statement available on the investigation.
FERC added that it was looking at ways to improve price transparency on the wholesale natural gas market.
"Much of the information available to the commission and natural gas market participants is aggregated and therefore does not provide full market visibility or price transparency," the regulator said in a statement.