With the acquisition of Atlus USA complete, SEGA of America will now be the sole publisher of the firm's titles in the Americas.
Atlus' parent company was purchased by SEGA in 2013 ¥14 billion ($141 million).
Thanks to the expertise of Atlus, SEGA has been able to localize Japanese franchises such as Yakuza for western audiences.
"After nearly a year working under the Sega Games division, both SEGA of America and Atlus U.S.A. have thrived and released a combined total of 23 game products," said Atlus CEO Naoto Hiraoka in the press release.
"Between Atlus' ability to localize and release Japanese video game products efficiently and the strength of Sega of America's reputation as a leading publisher in the industry, the situation could not be more symbiotic for both companies."
Each company will continue to act autonomously, with neither games nor products being "adversely affected by the publisher unification." This includes the Atlus logo and brand.