Customer take-up of Carphone Warehouse/TalkTalk's free broadband service has slowed in the last month, according to newspaper reports.
Earlier this year the ISP's decision to make broadband free to its customers resulted in enormous public demand, with around 340,000 customers signing up in the first eight weeks.
However, uptake during the second quarter of this year has fallen to 95,000, according to a report in the Times.
The previous quarter had seen 126,000 customers sign up to the telecommunications giant's service.
TalkTalk is expected to cite increased competition among broadband providers all offering increasingly attractive bundles as the reason for the decline.
However, "strong progress on transferring customers to its own network" will offset the decline in new custom, the Times predicts.
When TalkTalk initially launched its innovative free broadband bundles it struggled to cope with burgeoning demand, while technical problems with transferring customers are likely to have seen the ISP incur considerable costs.