EBITDA was SEK 304.2m, down 28%, while operating income was SEK 212.5m, a 38% decrease. Casino revenue also fell 12% to SEK 942.2m.
However, despite decreasing 7% to SEK 314.6m, sportsbook revenue would be in line with last year, excluding all revenue from the football world cup.
Betsson attributed the decline to "continued weak trends in Sweden and the Netherlands," which has seen the operator’s revenue fall 3% for the year-to-date, to SEK 3.89bn.
The operator outlined plans to "outgrow" the Swedish market through acquisitions, while compensating losses with subsidiary revenue in other markets.
Betsson AB CEO Pontus Lindwall said: "Like the previous quarter, the third quarter has continued to pose challenges for us, as well as for several other companies in the gaming industry.
"As the conditions in Sweden have not been right for large marketing investments, activities have been reduced and reallocated to other markets where they provide better returns.
"However, we are certain the Swedish market will improve and we stick to our long-term ambition to increase our share in this re-regulated market."