MADISON, Wis. - A federal judge in Wisconsin who ruled that a cash-balance pension plan violated the Employee Retirement Income Security Act 29 U.S.C.S. § 1001 et seq.,in calculating lump-sum distributions paid to a class of participants who left their employment before reaching normal retirement age on Aug. 24 ordered that the plan pay the class more than $18.67 million in additional plan benefits and prejudgment interest (Lawrence G. Ruppert, et al. v. Alliant Energy Cash Balance Pension Plan, No. 08-127, W.D. Wis.; 2012 U.S. Dist. LEXIS 120432).