Chatchai Thiamthong, financial director of BEC World, which operates the channel, said 20 per cent of slots remained unbooked.
"We stopped being the market leader in 2001, but we continued to behave like the market leader, raising our rates each year," he said.
"This has caused us a lot of problems, because our competitor is probably cheaper now in terms of cost per viewer." Channel 3 led the market until 2000, with 40 per cent of primetime viewership against Channel 7's 37 per cent. However, the most recent data shows Channel 7 with 40 per cent of primetime viewers against Channel 3's 28 per cent."The priority at the moment is to close this gap," Chatchai said.
Channel 7, meanwhile, is set to go ahead with its own rate hike this October. This is expected to be around 10 per cent for primetime slots.