Chicago Baby Bell Ameritech Inc has definitive agreement to acquire CyberTel Financial Corp and its subsidiaries and CyberTel RSA Cellular Ltd Partnership for a total price of about $512m cash, from CyberTel management and from affiliates of JMB Realty Corp, Chicago: CyberTel and its affiliates provide cellular phone service in the St Louis Metropolitan Service Area which includes portions of Illinois, and in southeast and central Missouri, covering a 3m population.