Bangladesh Telecommunication Regulatory Commission (BTRC) has recently allowed Grameenphone (GP) to sell unused pre-approved old numbers.
According to GP sources, the approval was given on Thursday and GP started to sell those unused SIMs since Friday.
However, GP had been asked to only sell SIMs that were not in operation for over 450 days.
BTRC officials said the operator is not allowed to sell any new SIMs.
Unless the BTRC finds GP improving its quality of services, it will not be allowed to sell new SIMs, an official added.
The telecom watchdog banned Grameenphone from selling new SIM cards from June 30 for what it said was the operator's failure to provide quality service.
Although the BTRC banned Grameenphone from selling new SIMs on the grounds of call drops and low service quality, the network provider had earlier passed the regulator's test in this regard.
Grameenphone lost eight lakh customers in July and its number of customers stood at 8.40 crore by the end of that month.