At the same time, the company added that it had seen a marked recovery in trading since the end of September.
"The introduction of a 5 percent turnover tax on sports betting in Germany, revenue decline in poker and continued pressure on consumer spending, particularly in parts of southern Europe, held back our performance in the third quarter," the firm said in a statement.
In Germany, the tax rule which came into effect from July 1 contributed to an 8 percent decline in the amount wagered on sports betting as Bwin.party removed short-odds bets. Year-on-year sports betting revenues fell 2 percent to 828.3 million euros, with unfavourable European soccer results also a factor.
Poker net revenue fell 29 percent year-on-year to 37 million euros, continuing a recent decline, although the firm said the imminent integration of its dotcom poker networks would provide a major catalyst for growth.
The group said that a recent upturn in business had been driven by a strong recovery in sports betting, with average daily net revenue in October up 19 percent on the previous quarter. It said it was confident about its full-year result.