CINCINNATI - A federal district court erred in ruling that the filed-rate doctrine deprived it of jurisdiction over electricity purchasers' claims that Duke Energy Corp. violated the Robinson-Patman Act (RPA) 15 U.S.C.S. § 13 by paying rebates to certain customers that withdrew opposition to rate increases, the Sixth Circuit U.S. Court of Appeals ruled June 4 (Anthony Williams, et al. v. Duke Energy International, Inc., et al., No. 10-3604, 6th Cir.; 2012 U.S. App. LEXIS 11189).