RIO DE JANEIRO -(Dow Jones)- The board of Brazilian long steel maker Gerdau (GGB, GGBR4.BR) approved a share buyback program, the company said in a regulatory filing on Monday Gerdau plans to buy back up to 1.2 million preferred shares, or about 0.2% of outstanding preferred shares. The buy back will take place between Friday and Feb. 3, Gerdau said. Gerdau shares closed Friday at 25.98 reals ($14.31). Brazilian markets were closed Monday for a Sao Paulo state holiday. -By Jeff Fick, Dow Jones Newswires; 55-21-2586-6085; jeff.fick@dowjones.com