All five original members of Boyzone are to begin a UK tour in May, which will be their first in seven years.
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Ronan Keating, who left the Irish boy band to pursue a solo career, will join the group for the series of concerts.
"We've been talking about getting back together for some time now. I can't wait to be back on the road and all the guys feel the same." Keating said.
The 10-date tour is due to start on 30 May at London's O2 arena, and will end in Glasgow on 23 June.
Earlier this month the group announced a one-off reunion for a performance on the BBC's Children in Need charity show, which takes place on Friday.
Keating said the rehearsals "made us want to tour together again".
He added: "Our live shows were always great fun but this time it will definitely be the best night out ever."
Keating and his fellow group members Stephen Gately, Shane Lynch, Mikey Graham and Keith Duffy formed Boyzone in 1994.
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They went on to have 16 consecutive top five hits, which included six UK number one singles and four number one albums.
Boyzone are one of a number of 1990s groups who are reforming.
Take That are about to start touring the UK for the second time since they reunited last year, while the Spice Girls, who have released their new single Headlines (Friendship Never Ends) for Children in Need, start their world tour in December.