Exhibit 23.4 CONSENT OF INDEPENDENT ACCOUNTANTS We consent to the incorporation by reference in the registration statement of MasTec, Inc. and subsidiaries on Form S-4 (No. 333-46361) of our report dated February 25, 1998, on our audit of the consolidated financial statements of Sistemas e Instalaciones de Telecomunicacion, S.A. (Sintel) and subsidiaries as of December 31,1997 and for the year then ended, which report is incorporated by reference in this Annual Report on Form 10-K. ARTHUR ANDERSEN LLP Madrid, Spain March 27, 1998