Scottish media company STV is expecting its TV advertising revenue to rise at a lower rate than the overall market in the third quarter of this year.
The ITV licensee said ad revenues should rise by 10%, well below a total UK TV market forecast of 17%.
The company said it was being hampered by its regional advertising business, which is expected to be down.
STV reported a surge in underlying pre-tax profits and turnover in the first half of 2010.
Turnover was up 20% year-on-year at £50m, while pre-tax profits rose to reach £6m.
The media group said overall broadcasting revenues were up 21% year-on-year in the first half to reach £44m, with operating profits doubling to £8m.
Rob Woodward, chief executive officer, said the group had "made great strides" over the last six months.
He added: "However, whilst there is an improvement in the market, we nevertheless remain cautious about the future macro economic climate."
Meanwhile, there is continuing uncertainty over exactly what form STV's television news may take in the future.
The company has argued that the existing set-up is unsustainable in the medium term without public money.
But the UK coalition government scrapped plans for a pilot scheme which would have seen a group, led by several Scottish newspapers, receive public money to provide news programmes for the channel.