EBITDA was SEK 196m, a fall of 14%, while profit after tax was SEK 97m, a 37% drop.
Revenue for the year-to-date was SEK 1.3bn, a decrease of 3% from 2018.
During the quarter, NetEnt launched games with several operators in Pennsylvania and with DraftKings in New Jersey.
Last month, the operator acquired Red Tiger for an initial fee of £197m ($253.7m), planning to utilise the supplier’s UK market presence and customer portfolio.
Red Tiger generated revenue of SEK 30m since the acquisition at the beginning of September.
Therese Hillman, NetEnt CEO, said: "We continue to see a challenging situation in some of our largest markets in the third quarter.
"The primary reason for the lower revenue was attributed to continued weak developments in the Swedish market.
"On the positive side, it’s worth highlighting the US, with continued strong growth in New Jersey and a great start in Pennsylvania during the quarter.
"We expect our slot games, including Red Tiger’s portfolio together with live casino, will contribute to solid growth for NetEnt in 2020."
