The UK festivals - which take place over three days at the end of August and share the same line up - will include headliners Guns N' Roses, Arcade Fire and Blink-182 - as previously announced - over three days and a number of different stages.
Other acts which officially joined the bill today (13.04.10) include US indie rock groups Girls and The Walkmen.
Meanwhile legendary guitarist Slash - formerly of Guns N' Roses and Velvet Revolver - has been added to the line up of the Download heavy metal festival in Donington Park, Leicestershire, UK which takes place from June 11th to the 13th.
He is one of 30 acts added to the bill today, alongside The Used, Cancer Bats and The Damned Things.
For more information visit www.downloadfestival.co.uk or readingfestival.com.