Celtic have decided not to appeal UEFA's £12,764 fine over illicit chanting during the side's Europa League clash against Rennes at Celtic Park.
The Scottish Premier League club were fined by the European governing body following offensive songs sung by the Celtic fans.
A statement from chief executive Peter Lawwell said: "The heavy fine imposed by UEFA is an indication of the seriousness with which it treats such matters. We would re-iterate our own position that however small a minority is involved, such chanting is not welcome at Celtic Football Club.
"Clearly, it is very disappointing and a source of real regret amongst our supporters that Celtic´s proud history of exemplary conduct has been tarnished in this way by such a tiny minority.
"However, this is a clear warning that such behaviour will not be tolerated and together, Celtic Football Club and our supporters will do all we can to ensure that this incident is not repeated.
"We would like to thank our supporters for their magnificent conduct since the match against Rennes. We are proud of the fantastic and positive reputation we have established across Europe over many years, and the club and our fans will be doing all we can to ensure that this is protected."
Celtic defeated Rennes 3-1 on home turf during the match last month.