Broadcaster ITV said it had seen a sharp fall in the amount of money it takes from premium-rate quiz and game show phone-ins.
The 20% decline for March and April came after the television industry was rocked by a series of allegations relating to the apparent duping of viewers.
ITV said all its current output had been cleared by an independent review, but warned it was unclear when consumer confidence would return.
The broadcaster said revenues from ITV Play, which runs during the night on ITV1 and ITV2, were running at a significant reduction from 2006.
It added: "Other premium rate telephone services revenue is down by approximately 20% in March and April and concerns remain about when consumer confidence in this area will be restored."
ITV said it had strengthened its procedures to comply with or exceed the provisions issued by premium rate telephone regulator ICSTIS.
Meanwhile, the group said advertising revenues at ITV1 remained under pressure after a decline of 9.6% over the first half of 2007. Total advertising revenues, including the contribution from digital channels, were 5.7% lower.
ITV said the wider UK television advertising market had stabilised, with revenues flat in the first six months of the year. The broadcaster's own performance was weaker because of the impact of the Contract Rights Renewal (CRR) mechanism, which reduces the amount that ITV advertisers have to pay if audience figures fall.
Ahead of the company's annual meeting, executive chairman Michael Grade said there were encouraging signs after ITV1's share of commercial impacts - a key viewing measure - showing signs of stabilising.
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Mr Grade said: "I'm encouraged by the progress we've made so far this year, but there is still a great deal more to do. We are taking steps to stabilise our core business and ensure future growth by reviewing the best allocation of our current resources."
