Ulster's director of rugby Les Kiss has left the Irish province by mutual consent following the team's recent poor run of results.
The ex-Ireland assistant coach's final game in charge on 21 January saw Ulster exit from the European Champions Cup after a heavy defeat by Wasps.
An Ulster statement confirmed Kiss's departure and said head coach Jono Gibbes would take charge of the team.
Australian Kiss, 53, assumed control in November 2015.
That followed a short interim stint in the Ulster post the previous season following the sacking of Mark Anscombe in the summer of 2014.
In his first two years in charge, Kiss' side reached the Pro12 semi-finals but last season they failed to make the play-offs and their form has dipped further in the current campaign.
His contract was scheduled to run until the summer of 2019.
European success proves elusive
European success has also proved elusive during Kiss' three-year reign with Ulster missing out on the knockout stages in all of his seasons in charge.
Ulster's statement on Wednesday evening confirmed that Kiss' departure would be "effective immediately".
"Ulster Rugby would like to thank Les for his commitment and wish him well in his future career," continued the statement.
"Head Coach, Jono Gibbes, will assume responsibility for all coaching matters and will lead the current coaching team of Dwayne Peel, Aaron Dundon and Niall Malone. A review will be conducted to ascertain if additional coaching expertise is required."
A further statement from the Irish Rugby Football Union praised Kiss for his "enormous contribution to Irish rugby".
Kiss was Ireland defence coach for seven years before his appointment to the Ulster job and he helped Ireland win the Grand Slam in 2009.
Kiss' backroom changes for this season
After last season's disappointing campaign, Kiss opted to change the backroom team as head coach Neil Doak and Allen Clarke departed with Gibbes and former Wales international Peel drafted in.
However after a promising opening to the season as Ulster won their first four Pro14 games, the Irish province have since managed only four victories in nine games in the new-format competition.
Two additional play-off spots are available this season with two quarter-finals also taking place but Ulster are facing a major battle to hold on to third spot in Conference B with Scarlets and Leinster out of sight at the top of the table.
Champions Cup wins home and away over Harlequins in early December appeared to have lifted the pressure on Kiss as they put themselves back in the frame for a European quarter-final spot.
However, a humiliating 44-16 Pro14 defeat by Connacht followed on 23 December and while they fought back from 17-0 down to beat 14-man Munster on New Year's Day, Kiss' side were hammered 38-7 by Leinster five days later.
Ulster regrouped to keep their Champions Cup hopes alive by beating La Rochelle on 13 January but an insipid display in Coventry a week later as they lost 26-7 against Wasps saw them crash out of Europe.