Once again there is speculation out of England about a Led Zeppelin 40th anniversary reunion world tour set for £250 million ($500 million). This time, rather than coming from a promoter who may or may not have offered bucket loads of pounds, the speculation centered around David Coverdale of Whitesnake.

Coverdale said in the Mirror on May 5 that Zeppelin was "very likely" to tour and that he was expecting to be the opening act. "I'm expecting a call from Jimmy any day asking my band Whitesnake to support them on their world tour," he stated. "Am I on board? You bet. Probably worth billions! Unlike rolling out the wheelchairs with the umpteenth Rolling Stones world tour, a Led Zeppelin tour will be incredible."

TicketNews has not been able to find any industry executives with knowledge of a Led Zeppelin tour. Some were surprised that Whitesnake would be an opening act; some thought Zeppelin might not even have an opening act if the band toured.

Speculation of a Zep reunion resurfaced after Zeppelin reunited for a one-off benefit show last December at London's O2 Arena with Jason Bonham sitting in on drums for his late dad, John.

Zeppelin frontman Robert Plant has consistently expressed a disinterest in a reunion tour. He is currently touring with Alison Krauss through July 19 in support of their album, "Raising Sand." "Gone Gone Gone (Done Moved On)," the first single from the album, won a Grammy for "Best Pop Collaboration with Vocals."