KNOXVILLE (AP) — The Southern Environmental Law Center has sued the nation's largest public utility for failing to disclose full contracts related to proposed natural gas pipelines.

The Tennessee Valley Authority plans to shutter its remaining coal-fired power plants and get power from another fossil fuel — natural gas. The SELC requested copies of TVA contracts with two gas companies under the federal Freedom of Information Act. TVA supplied the contracts, but they were heavily redacted, according to the lawsuit last week.

In explaining the redactions, TVA said that the contracts contain confidential business information that is exempt from disclosure.

SELC attorney George Nolan said it appears that TVA has committed to purchasing gas before complying with its National Environmental Policy Act obligations to study alternative energy sources. TVA said in an email it has not made any final decisions.

SELC is seeking unredacted copies of the contracts and a declaration that TVA violated the Freedom of Information Act.