Intellect, which represents 1,000 UK-based software, IT services, telecom and electronics companies, surveyed its members for its CEO Trends and Business Optimism Survey.
Less than half the companies surveyed said they were "fairly" or "very" optimistic about their prospects in the next three months. This is down sharply on the figures for the previous quarter.
Nick Kalisperas, senior programme manager at Intellect, said: "The significant movement is in the fall in optimism. Companies are more realistic about their options. Only 48% are optimistic, compared with between 65% to 70% for the previous survey."
Kalisperas said there were only slight differences between the confidence in different sectors of the industry, with e-commerce and training providers the most confident and consultants the least optimistic.
The key business drivers in the next quarter, according to the survey, will be technology replacement (19%) and e-government (17%).
"With technology replacement, it could be more hope than expectation," Kalisperas said. "With e-government the money is more tangible."
The survey revealed deep scepticism that the government would achieve its target for getting all services online by 2005. Even though two-thirds believe it would not happen, 74% believe the target should be retained.
The skills shortage remains a thorny issue, with 46% believing the government was not doing enough to tackle the problem.
"There are more people in the marketplace, but it's a question of having the right skills," said Kalisperas.