The decrease in revenue has been attributed to the negative currency effects partly offset by organic growth as well as a positive net impact from acquisitions and divestments.
Organic revenue of the company grew by 3.1% in the first quarter this year due to a positive impact from non-portfolio revenue and contract transitions.
The company also reported a 4.0% decline in operating margin due to the impact of contracts phasing in and out, compared to 4.5% for the same period in the previous year.
ISS Group chief executive Jeff Gravenhorst said: “Our results for the first three months of 2018 were encouraging. We delivered solid organic growth, supported by contract launches and demand for non-portfolio services within our strategic customer segments.
“Our margin performance was as expected impacted by acquisitions and divestments and currency effects, as well as phasing in and out of significant contracts.
“We launched a number of major contracts, such as LEGO Group and an international food and beverage company, and we saw several new wins during the quarter, among others Royal Philips, a major international air carrier and a new customer in the pharmaceutical industry.
“We will continue to strengthen our business with the implementation of strategic initiatives and our focus on key accounts.”
In addition, operating profit declined from $139.4m last year to $121.5m and net profit declined from $70.7m last year to $29.4m this year.