ECONOMY

Ameritech Aims to Trim Management Ranks: Ameritech Corp. plans to trim its management ranks by nearly 13% by offering enticements to retire early, the regional telephone company announced. The Chicago-based holding company for Bell telephone utilities in the Midwest said it expects 3,000 of its 23,900 managers to take advantage of the offer. The managers will be offered pension benefits computed with three years added to their age and length of service. Those who accept must be off the payroll by Dec. 30.