Sales volume in the current quarter stood at 302,000 tonnes, it said.
The flood situation in Central and North Thailand, coupled with holidays in October and December, affected deliveries.
Construction-sector growth remains sluggish, slowing demand for reinforcing bars. This was partly made up by healthy sales of wire rods.
Net sales during Q3 FY18 of Bt5.743 million were similar to the previous quarter and 24 per cent higher compared to the same quarter last year, due to higher prices.
EBITDA in Q3 FY18 at Bt478 million was 11 per cent higher than the previous quarter and 14 per cent year on year due to better management of spread and improved product mixes.