INDIANAPOLIS (AP) — Indiana’s utility consumer counselor and public advocacy groups are raising questions about coal-buying agreements that have boosted Vectren Corp.’s profits at the expense of its customers, whose rates are among the nation’s highest.

The Evansville-based utility locked into expensive, multiyear agreements in 2008, when coal prices were at record highs, to buy nearly all of its coal supply for its coal-fired power plants from its subsidiary, Vectren Fuels.