Referee Rob Styles has contacted Bolton to apologise for mistakenly awarding a penalty to Manchester United at Old Trafford.

It is understood the match official has made private contact with the club to express regret at giving a spot-kick to United when defender Jlloyd Samuel fairly tackled Cristiano Ronaldo.

It is not the first time Styles has made an apology for a mistake on the field - last season he did so publicly to Liverpool for a penalty error when Steve Finnan challenged Florent Malouda.

United went on to win Saturday's match against Bolton 2-0 and even manager Alex Ferguson was surprised about the award.

Bolton boss Gary Megson said after the match that he would not welcome a call from Styles.

Megson said: "I don't want him to ring me up. I would have more respect from him if he just holds his hands up and says he was wrong."

Styles is likely to find out tomorrow that his mistake has cost him a Premier League match at next weekend.

Under the self-regulation policy of the Professional Game Match Officials Limited (PGMOL), the body responsible for top referees, officials who make mistakes usually miss out on refereeing a Premier League match the following weekend.