We have been in talks with Zane and his agent since November
The Bulls' Springbok fullback Zane Kirchner will take up a contract with Irish province Leinster later this year.
Despite a five-month long effort by the Blue Bulls Company (Pty) Ltd to have 28-year-old fullback extend his contract past the 31 October 2013 expiry date, the player's agent last Friday confirmed a two-year deal with the Irish province.
A final release date has not been established though and will be determined by the BBC board of directors, High Performance Manager Xander Janse van Rensburg said on Monday.
"We understand that an earlier release might be requested, but it is up to the board to approve that or not," Janse van Rensburg said.
"We have been in talks with Zane and his agent since November and although it is very disappointing to lose his services, we wish him well with the new phase in his career.
"From our side, with coach Frans Ludeke very involved and in regular consultation with Springbok management, we tried our best to keep the player in Pretoria, but could in the end not compete with the exchange rate and the expectations of Zane and his agent."
Commenting on the move, Leinster coach Joe Schmidt said: "Zane Kirchner is a quality international player and we believe that he will add genuine value to the Leinster squad over the next few years.
"He’s well balanced, fast and skilful and has featured for the Springboks in their last nine internationals.
"At 28 he is ideally placed to contribute to team performance while also passing on his experience to some of our younger outside backs."