The Football Association today hit Joey Barton with a 12-game ban and fined him £25,000 following his training ground assault on former team-mate Ousmane Dabo.

Barton had hoped to minimize his punishment by pleading guilty to the charge of violent conduct.

Half of the sentence has been suspended but can be imposed at any time up to the end of the 2009-10 season should Barton be found guilty of "any similar charge involving violence or be dismissed from the field of play for violent conduct [but not for serious foul play]".

The 26-year-old had already been sentenced to four months imprisonment, suspended for two years, over the 2007 assault on Dabo while they were at Manchester City.

The sentence was imposed in July while Barton was serving a 74-day jail term for an alcohol-fueled attack on two men in Liverpool last December.

A statement from the independent Regulatory Commission Chairman Maurice Armstrong said: "The Commission members wanted to punish the offence appropriately but give Mr Barton an opportunity to ensure his professional conduct does not falter again and ensure he is fully aware of the consequences should he make another serious error of judgement."

Barton appeared as a second-half substitute at Arsenal last Saturday - his first appearance since his release from prison - and was involved in an altercation with Samir Nasri.

Newcastle owner Mike Ashley then tried to sell him, against ex-manager Kevin Keegan's wishes, before last Monday's transfer deadline.

Barton has 14 days to appeal the decision.