Financial publisher Euromoney says its underlying revenues will drop around 5% in the fourth quarter, largely due to the company intentionally reducing the number of commodity events and training courses.
Reported revenues for the three months ended 30 September are expected to show a 2% increase, helped by favourable exchange rates.
"Trading has continued in line with the board's expectations, although financial markets have been subject to increased volatility and uncertainty following the UK's Brexit vote in June," Euromoney said in a statement.
Total revenues for the 12 months to 30 September period are forecast to show a 1% decrease on last year, and an underlying decline of 4%.
The firm expects profit before tax of around £100m ($130m) for the fiscal year, down from a profit of £107.8m in the previous 12 months.
Euromoney is one of the largest financial magazine publishers in Europe and is a member of the FTSE 250 share index.
It is scheduled to release its full-year results on 24 November.