Apple CEO Tim Cook has agreed to make a rare appearance - he's consented to speak at a non-Apple event next month. Cook will kick off the tech conference "D: All Things Digital" at the end of May.

"Walt Mossberg and I could not be more thrilled to announce that Tim Cook, CEO of Apple, will be the opening-night speaker at our 10th D: All Things Digital conference," wrote AllThingsD's Kara Swisher. This will be Cook's first appearance at the tech conference.

Cook's appearance at the tech conference at the end of May, will make his second appearance at a conference in recent months. Back in February, he appeared at the Goldman Sachs annual Technology and Internet Conference in San Francisco.

As AllThingsD notes, however, this will be his "first time being onstage at an event not run by Apple or for investors since he was named CEO last August." Though he spoke to a much larger audience than just investors, the Goldman Sachs conference cannot be labeled as a non investor-related event.

With this appearance, Cook will follow the footsteps of his predecessor, Apple founder and former CEO Steve Jobs, who made six memorable appearances at the conference over the last decade. Jobs' last participation in the AllThingsD's conference was in 2010, at D8. Cook is expected to discuss the direction of Apple, as well as the industry in general, at least from his perspective.

Cook has been the Apple CEO only since August, but he has a long history with the company. Before assuming his current role at the head of the company, he played a critical part as Apple's Chief Financial Officer, responsible for worldwide sales and operations, and also head of the company's Macintosh unit. Before joining Apple, Cook distinguished himself at Compaq, Intelligent Electronics and IBM.

The tenth edition of "D: All Things Digital" will feature an impressive speaker list. Major players in tech and media include Oracle CEO Larry Ellison, New York City Mayor Mike Bloomberg, and Federal Trade Commission (FTC) Chairman Jon Leibowitz. The popular tech conference will take place in Rancho Palos Verdes, California, on May 29 - 31.

(reported by Alexandra Burlacu, edited by Surojit Chatterjee)