Spending on research and development (R&D) by Northern Ireland companies fell by 15% in 2014, according to an official report.
The figures, from Stormont's Department of Enterprise, show spending of £403.5m compared to £472.6m in 2013.
However, there was a 21% increase in R&D spending by higher education institutions.
Overall, across the private and public sector R&D spending was down by 5% to £602.3m.
The report cautions that variations can occur from year to year due to the influence of one or two large scale projects, either starting or finishing.
It said this likely contributed to the decline in business R&D expenditure over the year.
The total number of companies spending on R&D increased over the year from 534 firms in 2013 to 657 in 2014.
The concentration of spending also moved away from the largest firms - the 10 biggest spending companies accounted for 43% of the total spend, compared to 60% in 2013.
Almost two thirds of R&D spending in Northern Ireland was by externally owned companies.
However, locally owned firms reported an annual increase of 24% in their R&D spending.
The Confederation of British Industry's director in Northern Ireland, Nigel Smyth, described that figure as "really encouraging".
"Almost 550 locally owned companies are now investing in R&D. This bodes well for the future growth of the economy which is increasingly been driven by innovation."
Mr Smyth added: "It is vitally important for the future growth of the economy that we continue to support more investment in R&D both in our companies and in our universities."