Sega Sammy, the Japanese games maker behind the Sonic the Hedgehog franchise, has launched a 706 million euro ($776 million) offer for Rovio Entertainment, the Finnish group that gave the world Angry Birds.

The 9.25 euro a share offer values the mobile games pioneer at almost 20 percent below the price at which Rovio went public five and a half years ago, when it debuted with a market valuation of 896 million euro.

In a joint statement, Sega Sammy said it had based its bid on projections that the global gaming market would expand to $263.3 billion by 2026. In particular, it said, the share of mobile gaming would grow to 56 percent of the overall market.