Robert Plant is to tour with country star Alison Krauss, dampening hopes of an immediate announcement that he and Led Zeppelin will tour themselves.
Krauss (left) has won more Grammy awards than any other female star
The pair, who released the album Raising Sand in October, will perform across Europe next May and are expected to go on to the US in the summer.
Tickets for their UK shows, beginning in Birmingham, have gone on sale.
Led Zeppelin played their first gig in 19 years in London on Monday, sparking rumours of a full-blown reunion tour.
While guitarist Jimmy Page has indicated his willingness to reform for such a project, singer Plant has always been reluctant to commit.
Fans on Led Zeppelin's official website expressed their disappointment at the news.
"Oh dear - no Led Zep tour in 2008," wrote one, while others likened Krauss to a Yoko Ono-style figure for keeping the band apart.
Raising Sand entered the US Billboard chart at number two and has received critical acclaim.
The European leg of their tour will conclude in London at Wembley Arena on 22 May.