Anderlecht and Club Brugge enjoyed a protected status, AA Gent didn't. Both Anderlecht and Club Brugge will meet a Greek and a Croatian opponent.
Anderlecht meet Zenit Saint Petersburg of Russia, AEK Athens of Greece and Hajduk Split of Croatia in Group G.
AA Gent face Sporting (Portugal), Lille (France) and Levski Sofia (Bulgaria) in Group C.
Club Brugge are confronted with Villarreal (Spain), Dinamo Zagreb (Croatia) and PAOK Saloniki (Greece).
Each group: home and return legs, six matches.
The top two teams in each group advance.