English referee Mark Clattenburg was cleared by the Football Association on Thursday of using racist language towards a Chelsea player, causing more embarrassment for the European champions in a difficult week.

Chelsea went public and lodged a complaint with the FA last month over "inappropriate language" allegedly directed at their Nigerian midfielder John Obi Mikel by Clattenburg during the home Premier League defeat by Manchester United. "The FA has concluded its investigation into alleged misconduct by Mark Clattenburg during the match between Chelsea FC and Manchester United FC on Sunday 28 October 2012. No disciplinary action will follow against Mr Clattenburg," an FA statement said.

The news comes after a bad public relations period for Chelsea, who sacked manager Roberto Di Matteo on Wednesday despite the Italian leading them to their first Champions League title in May.

Although Chelsea had suffered a blow to their hopes of a Champions League last 16 berth, the axing was unpopular with fans and his temporary replacement Rafael Benitez has not been greeted warmly by supporters given he previously bossed rivals Liverpool.

The Londoners, owned by billionaire Russian Roman Abramovich, have also been criticised in the media for standing by captain John Terry despite the FA finding him guilty of racially abusing Queens Park Rangers player Anton Ferdinand last year. He was cleared of a criminal charge.

Spaniard Benitez was unveiled on Thursday and indicated to a news conference that Terry would stay as captain under his stewardship.

Mikel charged

In a separate statement on Thursday, the FA said Mikel had been charged for breaching its rules.

"It is alleged that in or around the match officials' changing room at the end of the fixture, Mikel used threatening and/or abusive and/or insulting words and/or behaviour," the FA said. "The player has until Friday 30 November 2012 to respond to the charge."

The FA said the evidence for the accusation against Clattenburg had come from Mikel's Brazilian team mate Ramires.

"The details of the allegation were that following one or the other of the red cards issued during the second half of the game, Ramires heard Mark Clattenburg say to John Obi Mikel, "shut up you monkey". John Obi Mikel did not hear the alleged comment.

"Ramires, whose first language is not English, explained that his instinctive reaction was to seek confirmation from John Obi Mikel as to what the referee had said.

"John Obi Mikel, who was being spoken to by the referee, was much closer to the referee than Ramires and did not hear what it is suggested was said to him."

The FA said the other match officials, linked to the referee via radio - which in future will be recorded as a matter of course in the wake of the case - were adamant the alleged words were not uttered.

"There is nothing in the video footage to support the allegation," the statement continued.

'Truly frightening'

Clattenburg, 37, said he was looking forward to putting the incident behind him and concentrating on his refereeing.

"To know you were innocent of something but that there was the opportunity for it to wreck your career was truly frightening," he said as the referees' union called on Chelsea to apologise and give him compensation.

"Racism has no place in football and this experience should not discourage those to speak out if they genuinely believe they are a victim of abuse," he added.

"However, there are processes that should be adhered in order that any investigation can be carried out in a manner that is fair for all parties involved."

His final comment appeared to refer to Chelsea announcing their allegations to the media on the night of the game before they had made a formal complaint to the FA, a course of action which also led to widespread media criticism of the club.

Their initial accusations including a second allegation of inappropriate language by the referee towards Spanish midfielder Juan Mata but that element of the complaint was dropped.

This month, London's Metropolitan Police dropped an investigation into a complaint about Clattenburg made by the Society of Black Lawyers following the incident.

Chelsea issued a statement accepting the FA's decision but reiterating they were right to report the matter.

"The FA states Chelsea took the correct action following the Manchester United match and encourages all players who believe they have been either subject, or witness, to discriminatory abuse to report the matter immediately to the match officials on the day, and in turn to the FA," Chelsea said.

"The club also notes the charge brought against John Obi Mikel. While the player does not deny the charge, he will request a personal hearing to explain the mitigating circumstances.

"Chelsea FC has a duty of care, as do all employers, to act responsibly when such allegations are reported by employees. We did not take the decision to lodge a formal complaint with the FA lightly and followed the correct processes and protocols throughout."