The Court of Arbitration for Sport (CAS) on Thursday upheld a decision by football's European ruling body UEFA to refuse FC Sion re-entry to the Europa League after the Swiss club breached player recruitment rules.
FC Sion had lodged several appeals with Swiss courts after being thrown out of the competition, with Scottish club Celtic taking their place.
CAS said in a statement FC Sion "must now pay damages of 40,000 Swiss francs (32,600 euros) to UEFA" which will cover the body's legal costs.
FC Sion were thrown out of the Europa League on September 2 after being found guilty of fielding six ineligible players, with Celtic handed their place in the group stages despite losing the play-offs 3-1 on aggregate.
The Swiss club had taken their case to several regional courts and a court in Martigny ruled in their favour, allowing the six banned players to return.
FIFA appealed that decision in the Valais cantonal court, which in mid-November "overturned the decision" of the local courts, according to FIFA. The court instead "upheld the appeal submitted by FIFA and the Swiss Football League".