Ospreys have parted company with head coach Steve Tandy after six years.
Tandy, 38, replaced Sean Holley in February 2012 and led the Ospreys to the Pro12 title later that season, the only silverware of his reign.
"This is not a decision that has been taken lightly," Ospreys managing director Andrew Millward said.
"Steve has been an outstanding servant... however, we're aware that results have not been good enough this season and... a change is necessary."
At the start of this season Ospreys officials said Tandy would be in charge until at least 2020, but the team have struggled in the Pro14.
Ospreys are second from bottom in Conference A, with four wins from 13 games, and were knocked out of the European Champions Cup last weekend after a 24-7 defeat at Clermont Auvergne.
"While our long-term focus is now on finding a world-class replacement and continue building a squad for next season, we have a busy end of season Pro14 run-in for the coaches and players to focus on," Millward added.
"A statement will be made shortly who's going to be taking us on for the remainder of the season as an interim head coach."
Tandy's backroom staff of Gruff Rees, Allan Clarke and Brad Davis remain with the Welsh region and the likelihood is one of them will be in charge initially.
Backs coach Rees has already announced he will be leaving Ospreys at the end of the season after 13 years with the Swansea-based region.
It has been reported Cardiff Blues backs and attacks coach Matt Sherratt has signed a three-year deal to replace Rees at the Liberty Stadium.