EXHIBIT 15 October 6, 1995 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, D.C. 20549 RE: Aluminum Company of America 1. Form S-8 (Registration No. 33-24846) Alcoa Savings Plan for Salaried Employees 2. Form S-8 (Registration No. 33-60305) Long Term Stock Incentive Plan 3. Form S-3 (Registration No. 33-49997) and Form S-3 (Registration No. 33-60045) Debt Securities and Warrants to Purchase Debt Securities, Preferred Stock and Common Stock We are aware that our report dated October 6, 1995, accompanying interim financial information of Aluminum Company of America (Alcoa) and subsidiaries for the three- month period ended September 30, 1995, is incorporated by reference in the registration statements referred to above. Pursuant to Rule 436 (c) under the Securities Act of 1933, this report should not be considered as part of a registration statement prepared or certified by us within the meaning of Sections 7 and 11 of that Act. Very truly yours, /s/ COOPERS & LYBRAND L.L.P. COOPERS & LYBRAND L.L.P.