The Scottish band - who had hits with `Chelsea Dagger` and `Whistle For The Choir` and won Best British Breakthrough act at the BRIT Awards 2007 - have decided to part ways after five years together.
The trio - John Lawler, Barry Wallace and Gordon McRory, Known as Mince - will still pursue separate musical endeavours.
Posting on the band`s website, singer and guitarist John wrote: "Mince, Baz and I are working on music but not with each other.
"Your passion is appreciated more than we will ever be able to say. We`ll forever give our hearts and souls to music and to you guys who want to hear what we do."
The Fratellis caused a stir in the British music press in 2006, and their debut album -Costello Music- was a number two hit. Through extensive touring and festival performances the group developed a huge fanbase, though the release of 2008-s -Here We Stand- album failed to meet critical or commercial expectations.
In a separate post on their website, Barry was more reflective on the group-s achievements.
He wrote: "From the very first day we got together The Fratellis never had a plan as such, we knew we were good, we knew we had a chance to make it.
"Turns out we were right, everything fell into place and we`ve spent the last five or so years touring the world.
"At this particular point in time though we`ve found ourselves making music still but just not together. This is just the way it goes I suppose sometimes."
John is now playing with the band Codeine Velvet Club and Barry is reportedly in a heavy metal band, while Mince-s next musical endeavour has yet to be announced.