BenefitMall, which offers employee benefits and payroll services, is being sold by one investment group to another. The Carlyle Group has agreed to purchase the Dallas, Texas-based company from Austin Ventures. Terms were not disclosed. The deal is expected to close by January 1. Austin Ventures has owned BenefitMall for five years. The Dallas, Texas-based company offers a range of payroll services: online, advanced, full-service, construction and restaurant payroll.