Wales prop Adam Jones has hailed Cardiff Blues' "ambition and potential for the future" after being unveiled as their latest new signing.
The 33-year-old, whose move from the Ospreys was initially confirmed by his agents Big Red Management on Tuesday, has agreed what is understood to be a one-season deal.
British and Irish Lions Test tighthead Jones has been out of work since his Ospreys contract expired at the end of last term.
He has been training with his former club Neath, as any prospective new deal with the Ospreys hinged on a solution being found to the long-running dispute over a new agreement between the Welsh Rugby Union and Wales' four professional regions - Ospreys, Blues, Scarlets and Newport Gwent Dragons.
No agreement has yet been reached between the WRU and regions, even though the new season is less than three weeks away from kick-off.
Jones had also been linked to following Wales captain - and new Blues team-mate Sam Warburton - in signing a WRU contact, but the Blues have now secured his services.
Confirming that Jones had told them he would not be re-signing at the Liberty Stadium, the Ospreys said they were "disappointed" with the outcome.
Jones has won 95 Wales caps and has toured twice with the the Lions - 2009 in South Africa and last year's Test series-winning tour to Australia.
He made his Wales debut in 2003 and has been part of three Six Nations Grand Slam-winning teams. He also featured in three World Cup campaigns.
" This is about a new challenge for me," Jones said.
"At this stage in my career I want a new environment and to really push myself.
"I've been really impressed by the set-up at the Blues and the desire to achieve in the coming years under the leadership of (director of rugby) Mark Hammett. It is that ambition and potential for the future that excites me about this move.
"Obviously, I would like to thank everyone at the Ospreys - from the players and coaches to the wonderful supporters - who have been absolutely fantastic with me. I wish the region every success for the future."
Hammett added: " Adam has joined the Blues determined to achieve something special with us. He is as hungry as ever for success and a very driven man.
"Adam wants to make a difference, and that is exactly why we want him here.
"He will be great for the younger players to learn off, and he is a world-class tighthead prop who will add considerably to the squad we are assembling."
Jones will now pack down in regional rugby with his Wales and Lions front-row colleagues Gethin Jenkins and Matthew Rees.
And Blues chairman Peter Thomas said: " Adam is one of the very best props in Europe, and when it became clear he was available we acted quickly, in conjunction with our director of rugby, to secure his services over the last 48 hours."
In a statement, the Ospreys said they had worked closely with Jones over a lengthy period in an attempt to reach a satisfactory outcome.
" Adam Jones has today advised Ospreys Rugby that he will not be re-signing and instead has signed a contract with another region," the Swansea-based region said.
"We are disappointed with this outcome, having worked closely with Adam over a period of many months to find a resolution to the situation that satisfied all parties.
"An initial contract offer that was unconditional on any Participation Agreement was made as far back as 2012, an offer that was declined by the player.
"A further unconditional offer was then made in October 2013, which was subsequently declined as he declared his interest in signing a central contract with the Welsh Rugby Union.
"When the proposed central contract failed to materialise we re-entered negotiations and, in good faith, made a new contract offer to the player which was dependent on the terms of any new Participation Agreement which may be concluded.
"As has been widely reported, that offer still remains on the table.
"While we remain in a difficult situation in terms of no resolution to the Participation Agreement and not knowing our full revenue stream for 2014/15 and beyond, our financial forward planning allowed us to re-contract 16 players, as well as completing the signing of eight new players for the coming season.
"Unfortunately, with Adam rejecting unconditional offers that were made prior to the expiry of the previous Participation Agreement, the reduction in guaranteed income post-December 31 had a direct impact on our ability to re-contract, particularly with other player commitments already completed."