Siam Cement Plc, 30 percent-owned by the Thai royal family, said profit in the third quarter may rise for the first time in five periods as record petrochemical product margins counter a decline in building material sales. The improved outlook means full-year earnings may match those of last year, President Kan Trakulhoon, pictured, said in an interview. However profits fell 8.2 per cent to 17.2 billion baht ($457m) in the first half of 2006.