Metallica are to play the London leg of Live Earth.
It's been widely rumoured as the band are playing Wembley the following night as part of the 'Sick of the Studeo Tour'.
A download of their performance at the climate change awareness gig will be available immediately after the gig.
Fans will be charged a small fee for the set, with all money raised benefiting four climate charities hand-selected by the band: Sierra Club, The Apollo Alliance, WWF and Rainforest Action Network.
The band will return to the new stadium on July 8 to headline their only full UK date this summer.