Source: Sharecast
Chief executive Imogen O'Connor said trading in the second half has "begun as expected", in line with previous years and usual seasonal trading patterns.
However, recent policy changes in the US relating to the timing of approved funding "is starting to affect institutional and academic customers, a sizeable proportion of our US business", she said.
Reductions in grants and funding mean that "several" pipeline opportunities have been cancelled or delayed beyond the current financial year.
The company, which makes sensors and software for the life sciences, entertainment, engineering and smart manufacturing markets, reported revenues of £20.1m for the first half to 31 March, down from £23.5m the year before.
However, Oxford Metrics said this result was in line with management's expectations due to strong comparatives, which included the final-stage delivery of its largest order in history.
The company swung to a statutory loss before tax of £0.7m, compared with a £3.7m profit a year earlier, while adjusted EBIT showed a loss of £0.4, down from £3.0m.
For the full fiscal year to end-September, adjusted EBIT is predicted to be in-line with the board's expectations "based on present market conditions and the conversion and execution of pipeline opportunities at their historical rate", the company said.
Shares were down 6% at 54.37, dropping to a low of 53p early on.