Brennan, 33, was handed the original suspension in March after being found guilty of assaulting supporter Patrick Banford during Toulouses fractious Heineken Cup win over Ulster.
The appeals panel upheld the original verdict but ruled a life ban was disproportionate and should be reduced.

Brennan must still pay a fine of 25,000 Euros (£17,000) plus 5,000 Euros (£3,500) in compensation to Bamford. He is also liable for costs.

He retired as a professional with Toulouse in March but is banned from playing at all levels of the game.

He is also barred from participating in any European Rugby Cup tournaments in any capacity for the five years. Both suspensions run from June 1, 2007.

An ERC statement read: Having heard from Mr Brennan, several character witnesses and from ERCs disciplinary officer during the appeal hearing, the appeal committee found that although the incident was of a very serious nature, in their view the original suspension - which was the maximum available - was disproportionate and should be reduced.

The appeal committee therefore suspended Mr Brennan from playing rugby union for five years and furthermore imposed a five-year suspension on Mr Brennan from participating in ERC tournaments in any capacity.