Chicago-based insurance brokerage group Hub International Ltd. has acquired SilverStone Group in Omaha, which will form the base of a new regional platform covering the Great Plains, Business Insurance reported. SilverStone has additional offices in Council Bluffs, Iowa, and Sioux Falls, S.D. Silverstone handles commercial property/casualty insurance, employee benefits and personal lines coverage and has more than 4,600 employer clients and 3,700 individual clients, Hub said in a statement. The Hub Great Plains region will include Hub’s existing operations in Omaha, Sioux Falls and St. Paul, Minn. John Nelson, CEO of Silverstone, will be the president of Hub Great Plains.