The deal will combine two online bingo and casino businesses operating under various brands in several countries.
The deal includes Real Money Jackpotjoy which the companies say has a leading market share in the United Kingdom, and Real-Money Starspins, an online slot site launched two years ago in the U.K.
Under the agreement, Toronto-based Intertain will make an initial payment worth 425.8 million pounds including about 7.4 million of its shares valued at $14.73 per share.
The company will also make additional payments totalling up to 15 million pounds if the Jackpotjoy business meets certain financial targets.
Gamesys is expected to distribute the Intertain shares to its shareholders.
The founder and principal shareholder of Gamesys, Noel Hayden, will also join Intertain's board of directors.