Leinster's Jonathan Sexton is set for a move to France after it was confirmed he would not be renewing his contract with the Irish province.
The Ireland fly-half has been linked with a big-money move to Racing Metro and the Irish RFU said he would not be signing a new Leinster deal.
Last week, Ireland coach Declan Kidney expressed optimism that Sexton would remain with the provincial outfit.
However, the IRFU have been unable to agree terms with 27-year-old Sexton.
Sexton has been reportedly the subject of a £625,000 a year offer from Racing Metro and is believed to have held talks with the French club.
"We remained in the fight up until the last possible moment to keep Johnny in Ireland with a very strong offer," said IRFU chief executive Philip Browne.
"But, ultimately, following negotiations with the player's agent, we had no option but to take the decision that it would not be in the best interest of Irish rugby to chase the reported financial incentives being offered.
"The IRFU has made a commitment to, and been largely successful in, keeping as many Irish players as possible playing full-time in Ireland.
"However, we have always recognised that some of our players will be targeted by overseas clubs with offers which, quite simply, are not within our orbit."
The statement spoke of the IRFU's "disappointment" but wished him "continued success" with his career.
"Johnny is a major talent and his full-time presence in Ireland will be missed, particularly by Leinster," continued Browne.
Leinster coach Joe Schmidt added that the offer Sexton had received "is exceptional, even by French standards".
"But I know it was still a tough decision for him," said Schmidt.
"Naturally, I'm disappointed. I've really enjoyed Johnny's input over the last few years and he has added tremendous value to the Leinster environment both on and off the field."
Sexton made his Ireland debut in November 2009, not long after he became the first-choice 10 at Leinster.
He was one of the top earners in Ireland after gaining an international contract with the IRFU but any offer from Racing Metro will dwarf any annual package his home union could offer.