Exhibit 15 July 29, 1999 Securities and Exchange Commission 450 Fifth Street, N.W. Washington, DC 20549 Ladies and Gentlemen: We are aware that United Technologies Corporation has included our report dated July 20, 1999 (issued pursuant to the provisions of Statement on Auditing Standards No. 71) in the Prospectus constituting part of its Registration Statements on Form S-3 (Nos. 333-26331, 33-46916 and 333-74195), in the Registration Statement on Form S-4 (No. 333-77991) and in the Registration Statements on Form S-8 (Nos. 333-21853, 333-18743, 333-21851, 33-57769, 33- 45440, 33-11255, 33-26580, 33-26627, 33-28974, 33-51385, 33-58937, 2-87322, 333-77817, 333-77991 and 333-82911). We are also aware of our responsibilities under the Securities Act of 1933. Yours very truly, /s/ PricewaterhouseCoopers LLP PricewaterhouseCoopers LLP