Wisconsin regulators are taking closer look at Xcel Energy's records.
Their scrutiny is the result of concerns in Minnesota over the accuracy of Xcel's reliability figures.
The Minnesota Public Utilities Commission has ordered its state commerce department and attorney general's office to investigate claims by current and former employees. They say the company alters data to make it appear as though power failures are shorter than they really are.
The utility is required to meet certain state standards that measure the reliability of its service.
Wisconsin Public Service Commission spokeswoman Annemarie Newman says regulators may ask Xcel to provide additional information on figures filed in this state.
An Xcel subsidiary -- Northern States Power -- serves 227,000 electrical customers in western Wisconsin.