TOKYO— Nintendo Co. ’s next two smartphone games will be free to download, the company’s partner said Wednesday, increasing the likelihood that the long-loved console titles would rank high in competitive app stores.

Tokyo-based DeNA Co., which develops and runs its own smartphone games, teamed up with Nintendo, the Kyoto-based videogame powerhouse, last year for the joint project. The companies released their first title, Miitomo, earlier this year, and are expected to produce four more by March 2017.

Nintendo said last month that the next two titles for devices running Apple Inc.’s iOS and Google parent Alphabet Inc.’s Android software would be rolled out by this autumn.

The titles are role-playing franchise “Fire Emblem” and community simulation “Animal Crossing,” both popular game series from the company most known for Mario the plumber and “The Legend of Zelda.”

“‘Fire Emblem’ and ‘Animal Crossing’ are both free-to-start apps,” DeNA Chief Executive Isao Moriyasu told The Wall Street Journal. A Nintendo spokeswoman confirmed Mr. Moriyasu’s comment.