Rovio Entertainment Ltd., the Finnish maker of the “Angry Birds” mobile game, on Wednesday said it plans a sequel to its successful animation movie based on the irascible fowls.

With a budget of $73 million, “The Angry Birds Movie” has so far brought in $346.9 million at the box office world-wide since its release in May, according to Box Office Mojo, of which $107.5 million was made in the U.S.

“We...