KENNY SHIELS left Kilmarnock yesterday, apologising for his clashes with the Scottish Football Association and urging the club to appoint Jimmy Nicholl, his assistant, and player Garry Hay as his successors.

Kilmarnock terminated the contract of Shiels with immediate effect yesterday for "football and regulatory" reasons. The statement added that it was "mutually agreed that his contract as manager should end".

Shiels was last week given a four-week ban by the Scottish Football Association for bringing the game into disrepute after questioning the impartiality of the SFA's judicial panel and the integrity of Celtic. Kilmarnock were also found guilty of failing to ensure that Shiels complies with SFA protocol after a series of controversies involving the 57-year-old manager.

The departure of the manager was greeted angrily by fans but Shiels, who won the Scottish Communities League Cup with Kilmarnock just more than a year ago, was contrite.

"I have to be self-analytical over this part of my experience with Kilmarnock," he said. "I saw the need to protect the club every time I felt it had been the victim of injustice and every time I thought something had gone against us which should not have. I may have been over-protective and I apologise for that," he said of the clashes with the SFA."

Shiels refused to criticise Michael Johnston, the club chairman, over the parting of ways but urged the board to bring continuity to the club by appointing Nicholl, his fellow Northern Irishman, as manager and Hay, the 35-year-old player, as his assistant.

Inevitably, Allan Johnston, the former Kilmarnock player and successful Queen of the South manager, will be linked with the post, as will Paul Hartley, who has enjoyed an impressive start to his managerial career at Alloa Athletic.

Shiels insists he has left the club with a bright future. "I believe with the youngsters coming through that there is the foundation of a good side for next season. But I believe there could be an exceptional season in 2014/15. I believe we had the makings of a team that could finish second or third in the SPL and qualify for Europe."

The Kilmarnock statement said: "Unfortunately season 2012/13 saw the club exit the league cup at the first hurdle and go on to record our poorest home record since season 1980-81, culminating in seven matches without a victory at Rugby Park to exit the Scottish Cup and miss out on the top six and then drop to ninth place with five defeats in our final six SPL fixtures."

It also addressed the clashes with the football authorities: "A difficult relationship with the Scottish FA resulted in several touchline bans and recent comments regarding a fellow SPL club and the Scottish FA judicial panel incurred a further suspension which would have seen Kenny commence next season in the stand, rather than the dug-out.

"As a result, the club was also prosecuted by the judicial panel's compliance officer at a hearing on June 6 and will discover the penalty to be imposed on June 21."

Shiels left his post as head of youth at Tranmere Rovers to become assistant to Mixu Paatelainen in June 2010, succeeding the Finn in the summer of 2011.