U2 have extended the opening leg of this summer's world tour to promote new album "No Line On The Horizon"

Tickets for the "360° Tour" dates go on-sale on Friday, March 20, with the band playing across Europe, the UK and onto North America.

New concerts in Gothenburg, Amsterdam and Milan have now been announced and a second gig in Dublin also added.

As previously reported, the tour is expected to feature a revolutionary 360° stage design and cylindrical video screen.

U2 will play:

June 2009

30 Nou Camp, Barcelona

July

07 San Siro, Milan

11 Stade De France, Paris

15 Parc Charles Ehrmann, Nice

18 Olympic Stadium, Berlin

20 Arena, Amsterdam

24 Croke Park, Dublin

31 Ullevi, Gothenburg

August

06 Slaski Stadium, Chorzow

10 Maksimir Stadium, Zagreb

14 Wembley Stadium, London

18 Hampden Park, Glasgow

20 Don Valley Stadium, Sheffield

22 Millennium Stadium, Cardiff

September

12 Soldier Field, Chicago

16 Rogers Centre, Toronto

20 Gillette Stadium, Boston

24 Giants Stadium, New York

source: yahoo