The state of Illinois has adequately alleged that three temporary staffing agencies and a client they share committed antitrust violations, a judge held.In a written opinion last week, Cook County Circuit Judge Raymond W. Mitchell declined to throw out a lawsuit accusing the agencies of violating the Illinois Antitrust Act by allegedly entering into no-poaching and wage-fixing agreements with one another.The suit also alleges the agencies — Elite Staffing Inc., Metro Staff Inc. and Midway Staffing Inc. &mdash …