In 1968, the move got adapted into a Broadway musical, renamed Illya Darling. Totally unlike most musicals adapted from movies (if not all...), the stage show got major attention because Melina Mercouri re-created her starring role. (As I noted in an earlier post, Anthony Quinn also re-created his famous role of Zorba, in the stage musical version of Kander and Ebb's musical version, but that was for the revival, so I draw a slight difference. Oddly, both for were for Greek-related stories. The only other case I'm aware of is Julie Andrews doing both the film and stage musical versions of Victor, Victoria. There may be others, but I'm drawing a blank at the moment. And Mercouri, as far as I know, was the first.)
The stage show for Illya Darling was also directed by the 1960 film's director, Jules Dassin. And the music was by Manos Hadjidakis, who had written the score to the film -- something which had the added benefit of the stage show being able to incorporate the famous title song into it. The lyrics were by Joe Darion, who was most famous for having written Man of La Mancha three years earlier.
Illya Darling didn't get especially good reviews, but had a respectable run of 320 performance, clearly on the strength of Mercouri's performance.
Here are 8-1/2 minutes from the show, from an appearance on The Ed Sullivan Show. It's sort of an odd choice. For the first half of it, Melina Mercouri -- pretty much the reason people went to see the show -- does literally nothing but sit and watch others dance and sing around her. Then she does at last get to perform -- but it's to dance only, no singing. (Having heard the cast album, she's not the strongest singer, but she carries her songs well). Finally, when they break into that famous title song, she does at last sing, which they save for around the seven-minute mark. Still, it's a quite entertaining clip and wonderful piece of history -- even if it was an offbeat way to promote the show.