Summary List PlacementThe public relations industry is dominated by giant agencies, but nimble competitors are rising up to challenge them. The four largest public relations firms — FleishmanHillard, Edelman, Weber Shandwick, BCW — use their scale advantage to roll out global campaigns, while their vast resources ensures they can shovel money into building out growing areas, said Art Stevens, managing partner at Stevens Group, a mergers and acquisitions consulting firm. Despite these advantages, small players are giving the Goliaths a run for their money. "New agencies spring up every day led by aggressive, ambitious and farsighted PR professionals," Stevens said.