The Daily Mail owner sold around 32.3mln Euromoney shares at 975p each raising gross proceeds of around £315 million.
Euromoney (LON:ERM) publishes the Euromoney magazine and shares tanked 9.2% to 1,017p on the news.
The Daily Mail & General Trust recently reported an 11% decline in adjusted operating profit for the 12 months to September 30. Revenue at Euromoney fell 4% on an underlying basis.
DMGT said today that as a result of the sale, the share of operating profits from joint ventures and associates in the year to end September 2017 is now expected to be around £65mln rather than around £25 million, as guided in December last year.
DMGT shares shed 2% to 776p in early deals.