Many producers like Hoa Phat Group, Viet Nhat, Viet Y, and Kyoei cut prices by VND300,000-500,000 ($12.81-21.36) a ton this week.
Prices have fallen by around VND3.5 million a ton in the last three months to VND14.4-15.7 million though they remain higher than last year's VND12.5 million.
The relentless fall comes amid weaker demand and falling production costs.
Steel output last month was 2.25 million tons while demand was for 1.99 million tons, both down 13% year-on-year.
Demand had fallen by 7.3% in the first six months of the year as the property market slowed on credit tightening by banks and falling demand in China.
Demand is unlikely to return in Q3 since it is the construction low season, and with inventories being high as well, prices would not go back up, BIDV Securities (BSC) said.
Mirae Asset Securities made a similar forecast citing high inflation. Steel output this year would fall by 10% to around 27 million tons, it added.
