Ravinia Festival officials announced Monday that Conlon has extended his contract for one more year and will lead its resident orchestra, the Chicago Symphony, for six more performances next July and August.
Conlon, 64, said in the written announcement of his impending exit that he needed time for other things.
"Everything has its time, and after 11 years I feel it is the moment to pass on this responsibility," he said. "I have worked year-round, including every summer, since 1974. There are things I wish to accomplish, both musical and personal, and I need dedicated time to realize these projects."
John Anderson, chairman of the festival board, said Conlon "will be missed almost as much as he is admired by the Ravinia family."
Conlon's commitment to L.A. Opera extends at least through 2017-18, following a five-year renewal of his contract in 2013. It will bring his tenure in the Dorothy Chandler Pavilion's orchestra pit to 12 years.
Also continuing for Conlon is his commitment to the May Festival in Cincinnati, an event devoted to choral music. He's heading into his 37th year as its music director, dating to 1979.
Ravinia, established in 1904 at a park north of Chicago in Highland Park, Ill., boasts of being "the oldest outdoor music festival in North America." It showcases classical music as well as jazz and musical theater. The main venue is a 3,500-seat outdoor covered pavilion with a large lawn that brings its capacity to about 15,000.
With Conlon's impending departure, the festival is faced with finding just its fifth music director since Seiji Ozawa inaugurated the position in 1964; he was followed by James Levine, Christoph Eschenbach and Conlon.
The just-finished 2014 classical season at Ravinia featured a strong helping of concert versions of Conlon-led operas, including Richard Strauss' "Salome" and Mozart's "Don Giovanni" and "The Marriage of Figaro."
In his final season as music director, he is scheduled to conduct five classical concerts in the main pavilion and a sixth in Ravinia's 850-seat indoor venue. The only opera on tap is Wagner's "The Flying Dutchman," on Aug. 15, 2015, which will be Conlon's final bow as music director.
Conlon will share not only concerts of standard repertoire, including pieces by Mozart, Mahler, Tchaikovsky, Shostakovich and Brahms, but also his passion for reviving the music of Jewish composers whose work was all but forgotten when it was banned by the Nazis. Alexander Zemlinsky's tone poem, "The Mermaid," will be performed as part of a program titled "Breaking the Silence."
Conlon will open L.A. Opera's season conducting six performances of Verdi's "La Traviata" starting Sept. 13. His website says he also has a November engagement leading New York's Metropolitan Opera in Shostakovich's "Lady Macbeth of Mtsensk."