Seeking to end an often chaotic legal saga, UEFA dismissed FC Sion's appeal against exclusion from the Europa League for fielding ineligible players in a playoff and confirmed Celtic's place Tuesday.

UEFA announced its verdict hours after the Swiss club, putting itself at the center of another confusing legal drama, claimed it was reinstated by a civil court's provisional ruling.

UEFA President Michel Platini confirmed Celtic will face Atletico Madrid on Thursday in Spain after he led an emergency meeting to consider Sion's flouting of football rules by pursuing a dispute in an outside court.

''This is ultimately about protecting clubs, the players and football itself,'' Platini said in a statement. ''We cannot accept that if one individual club does not get its own way then it goes through any possible system to force its will on the others.''

However, Sion president Christian Constantin, the combative force behind his club's legal battles, warned of further legal action against UEFA.

''The judgment of the Swiss court of (Tuesday) morning must be executed. That's all,'' Constantin was quoted telling Swiss daily Le Matin.

UEFA, which did not attend the civil process, said it rejected Sion's attempt to secure ''special privileges'' and ''circumvent'' established rules accepted by other clubs.

Celtic said on its website that ''clearly, (we) are pleased with the decision.''

However, Sion can challenge UEFA's ruling at the Court of Arbitration for Sport within 10 days of receiving the written legal grounds. It is pursuing a separate CAS appeal in a dispute with the Swiss league over blocked player registrations.

Sion appealed UEFA's disciplinary decision, which awarded Celtic 3-0 wins by forfeit in both legs of the clubs' Europa League playoff last month. Although Sion won 3-1 on aggregate, it used five players signed in breach of a FIFA transfer ban. Celtic played both matches under protest then formally complained to UEFA.

Ahead of its UEFA appeal hearing, Sion said it had booked a Wednesday morning flight to Madrid and reserved hotel rooms in the Spanish capital.

The session at UEFA headquarters was interrupted Tuesday for the three-man panel to receive details of the provisional ruling from a civil court in UEFA's home canton (state).

Sion said the emergency measure awarded by judges in Vaud meant it could face Atletico.

Sion lawyers went to civil courts, apparently breaking FIFA statutes, after losing verdicts at FIFA, the Court of Arbitration for Sport and the Swiss supreme court.

Sion broke FIFA transfer rules in 2008 by luring goalkeeper Essam El-Hadary to walk out on Egyptian club Al-Ahly in the middle of the season. It received a one-year transfer ban from the governing body of world football.

Platini said Tuesday that football should sanction clubs for ''using their influence and wealth to induce players to breach their contracts.''

''This is against all rules of sporting fairness,'' he said.

FIFA and UEFA believed Sion's ban took effect when the club exhausted an officially recognized appeal route at Switzerland's supreme court in January.

However, the legal saga continued because Sion contended that it served the ban cumulatively over a series of trading periods.

Platini said before the Europa League draw in Monaco last month that Sion's team against Celtic included players signed ''in clear violation of the ban.''

UEFA entered Sion in the draw with an asterisk against the club's name pending the outcome of Celtic's protests. The group also includes Udinese and Rennes.

Sion and Constantin have pursued many lines of legal attack and defense during more than three years of wrangling.

The club's holding company tried to launch a criminal action against FIFA secretary general Jerome Valcke and UEFA counterpart Gianni Infantino for allegedly coercing the Swiss Football Association to help persuade Sion to accept its punishments.

Public prosecutors in Vaud refused to accept the case last month.

In another move, Sion claimed that FIFA had dealt legally with the holding company and so the team's football operations should be exempt from sanctions.