EXHIBIT 99.3

CERTIFICATION PURSUANT TO 18 U.S.C. SECTION 1350, AS ADOPTED PURSUANT TO SECTION
906 OF THE SARBANES-OXLEY ACT OF 2002

     In connection with the Annual Report of Gerdau Ameristeel Corporation (the
"Company") on Form 40-F for the year ended December 31, 2005, as filed with the
Securities and Exchange Commission on the date hereof (the "Report"), I, Mario
Longhi, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C.
section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of
2002, that to the best of my knowledge:

1.   The Report fully complies with the requirements of section 13(a) or 15(d)
     of the Securities Exchange Act of 1934; and

2.   The information contained in the Report fairly presents, in all material
     respects, the financial condition and results of operations of the Company.


By: /s/ Mario Longhi
    ---------------------------------
    Mario Longhi
    Chief Executive Officer

March 29, 2006