* Two-year ban on Fenerbahce upheld on Wednesday
* Tromso and APOEL to replace Besiktas and Fenerbahce in group stages
* Dismissal of appeals adds to woes of Turkish sport (Adds UEFA statements, details, background)
By Daren Butler
ISTANBUL, Aug 30 (Reuters) - Turkish club Besiktas have been excluded from the Europa League this season after the Court of Arbitration for Sport (CAS) upheld a UEFA-imposed one-year ban from European competition for match-fixing, CAS said on Friday.
The decision comes two days after CAS dismissed an similar appeal by rival Istanbul club Fenerbahce for a two-year UEFA ban over a seperate match-fixing case, which along with a rash of doping cases has tarnished the image of Turkish sport.
The rulings were announced less than two weeks ahead of the International Olympic Committee (IOC) vote on whether Istanbul, Madrid or Tokyo will host the 2020 Olympics on Sept. 7 and could damage Turkey's hopes of hosting the Games for a first time.
Playing under appeal against the original ban, Besiktas beat Norway's Tromso 2-0 on Thursday in the second leg of their Europa League playoff, winning the tie 3-2 on aggregate, but the CAS ruling ends their campaign before the group stages.
"The Court of Arbitration for Sport (CAS) has today dismissed the appeal filed by Besiktas JK against the decision taken by UEFA," the Lausanne-based court said, issuing the decision without grounds due to the urgency of the matter.
UEFA said in a statement, its Emergency Panel had reinstated Tromso in the Europa League after CAS rejected Besiktas' appeal while APOEL FC from Cyprus were selected in a mini-draw among the playoff losers to take Fenerbahce's place in the tournament.
The Europa League group stage draw was to be held later on Friday.
Fenerbahce, beaten 5-0 on aggregate by Arsenal in a Champions League playoff, has said it would appeal the CAS decision in a Swiss federal court. It was not immediately clear whether Besiktas would take a similar step.
Fenerbahce and fellow Istanbul club Besiktas were banned in June after a protracted UEFA inquiry into scandals that emerged in 2011.
Fenerbahce, who won the 2010-11 title, were withdrawn from the following season's Champions League by the Turkish Football Federation as a result of their investigations into widespread match-fixing allegations which rocked the Turkish game.
The club were implicated in the scandal with suspicions raised over their 4-3 victory against Sivasspor which clinched the league championship on the final day of the season.
Besiktas were charged as a result of their involvement in the 2011 Turkish Cup final, which they won on penalties after a 2-2 draw against Buyuksehir Belediyespor.
Last July, a Turkish court convicted 93 defendants, including Fenerbahce chairman Aziz Yildirim, club executives and players, in connection with the case.
Yildirim was sentenced to more than six years in prison but was released from custody after launching an appeal, which is still ongoing.
In a separate blow to Turkish sport, the country's athletics federation on Wednesday banned double European 100m hurdles champion Nevin Yanit for two years over drugs violations, weeks after similar bans for 31 other local athletes. (Writing by Daren Butler; Editing by John O'Brien)