Bangladesh tea fetched an average of 178.56 taka ($2.50) per kg at the auction, compared with 186.78 taka in the previous sale.
The offerings in this sale were the largest so far this season, which met with much less demand, leaving a huge volume unsold, the National Brokers said in a market report.
However, there was strong demand for quality tea, which was in short supply, a senior official of the National Brokers said.
About 53 percent of the 3.4 million kg offered at the sole auction centre in Chittagong was unsold.
In the previous auction, about 32 percent of the 2.85 million kg on offer remained unsold.