Dennis Hanthorn, general director of the Atlanta Opera, has resigned.

Hanthorn, who led the group for eight years, stepped down July 31.

“After eight seasons, it is time for a change in leadership at the Atlanta Opera and for me to explore new opportunities,” Hanthorn said in a statement released by the organization.

Laura Soldati, a spokeswoman for the opera, said in an email Tuesday his departure was “a mutual and amicable decision.”

Ann Owens, an Atlanta Opera consultant and former executive director of the Houston Grand Opera, and a senior management group consisting of the opera’s artistic administrator, production manager, company manager and all senior-level staff members, including Music Director Arthur Fagen and Chorus Master Walter Huff, will lead the organization as it searches for Hanthorn’s replacement, Soldati said.

The opera is forming a search committee for its national search to replace Hanthorn, but no timetable on hiring his replacement has been set, Soldati said.

The organization will host its annual Opera Ball Sept. 15 at the St. Regis in Buckhead and will kick off its 2012-13 season Nov. 10 with “Carmen” at the Cobb Energy Performing Arts Centre near Vinings.