The deal would mark the end the independence of Finnish mobile game makers, which burst into the scene when Rovio launched its slingshot-bird game more than a decade ago.
The bid by Sega, famous for its own animal character, Sonic the Hedgehog, is also the latest high-profile acquisition in the gaming sector.
The offer, which represents a 19 percent premium over Rovio's closing share price on Friday, is part of Sega's "long-term goal" of expanding into the mobile gaming market, Sega CEO Haruki Satomi said.
"Among the rapidly growing global gaming market, the mobile gaming market has especially high potential," he said in a statement.
Angry Birds instantly became one of the most successful mobile games ever released when it made its debut in 2009, with a variety of birds flying through the air to crash into structures and take down armies of green pigs.
In 2016, the "Angry Birds" movie, produced by Sony Entertainment, was a massive success that grossed $350 million worldwide.
Rovio recommended that shareholders accept the offer.
The Finnish company, which employs over 500 people, reported a revenue of 317.7 million euros for 2022, with an adjusted net profit of 31.4 million euros.
Sega is aiming to open the offer period in early May and complete the deal in the third quarter, the company said.
A major player in video games in the 1980s and 1990s, the Japanese company went into decline after it failed to compete against Japanese competitors Nintendo and Sony's consoles.
Gaming companies are fighting it out for a slice of an industry worth hundreds of billions of dollars.
Sega Wants 'Angry Birds' Maker
HELSINKI - Japanese gaming group Sega has offered to buy the creator of the popular Angry Birds franchise, Finland's Rovio, in a deal worth more than 700 million euros ($770 million), the companies said Monday.