Its profit margin of 2.1% was a fifth of the rate in the first half last year, the company said in a financial report it sent to the Hanoi Stock Exchange.
The car market has been sluggish since the last quarter of 2022.
Thaco Group recently slashed the prices of many models it manufactures and distributes by hundreds of millions of dong (VND100 million = $4,114) to stimulate demand.
Thaco Group still has a sales target of over 120,000 vehicles for this year, including 96,000 passenger cars, 23,500 trucks and 1,500 buses and mini buses.
According to statistics from the Vietnam Automobile Manufacturers Association, Thaco sold some 58,000 cars in the first eight months of this year, down 40% year-on-year and only 48.3% of its target.