Milan, who beat the Spanish side in the 1994 European final, finished runners-up in Serie A last season and were in pot two for today's draw in Monaco.

That was always going to leave them with a difficult tie against one of the top seeds from pot one, and they landed the biggest in the three-time defending Primera Division champions.

BATE Borisov and Plzen complete Group H, with the first round of Champions League fixtures due to be played on September 13 and 14.

Barcelona's bitter rivals Real Madrid were drawn in Group D alongside Lyon in a rematch of last season's last-16 fixture, which the Spanish club won over two legs. Ajax, the 1995 champions, and Dinamo Zagreb also feature in the group.

Serie A champions Inter Milan face a tricky trip to CSKA Moscow in Group B, as well as fixtures against Lille and Trabzonspor.

Last season's beaten finalists Manchester United were given an apparently kind draw, with Benfica, Basle and Otelul Galati their opponents in Group C.

Four-time winners Bayern Munich will take on Villarreal, big-spenders Manchester City and Napoli in Group A, while Group E pits Chelsea against Valencia, Bayer Leverkusen and Genk.

Europa League holders Porto face two long trips east to take on Shakhtar Donetsk and Zenit St Petersburg, as well as Cypriot champions APOEL in Group G.

Group F sees Bundesliga title holders Borussia Dortmund go up against Arsenal, Marseille and Olympiacos.