MARSEILLE, France (AP) Marseille coach Marcelo Bielsa resigned over a contract dispute after his players lost to Caen 1-0 in their opening French league match on Saturday.

The former Argentina coach, widely credited for Marseille's return to prominence last season, was out of contract but said this week that he had found an agreement with club president Vincent Labrune to extend his tenure.

Bielsa, who took over in 2014, backpedalled on Saturday and gave his resignation letter to Labrune before speaking at the post-match news conference.

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''I cannot accept this situation of instability. I've given everything that I have to this team. I have finished my work here, I will return to my home country,'' said Bielsa, who has been linked with a move to Mexico as a possible replacement for sacked national coach Miguel Herrera. ''I'm not leaving to go somewhere else.''

Bielsa claimed he had made up his mind before Saturday's game.

''After three months of discussions, I could not accept that there were continual changes in the terms of my contract,'' he said.

Marseille goalkeeper Steve Mandanda was stunned.

''It's a very big surprise, we did not expect it at all,'' Mandanda said. ''It feels like a heavy blow, he was important to both the club and the team, we are disappointed.''

Bielsa impressed at times with his brand of attacking football, and Marseille was in contention for the league title last season before a run of four straight defeats in April ended those hopes.

Marseille ultimately finished fourth, and allowed Andre-Pierre Gignac, Andre Ayew, Dimitri Payet, and Jeremy Morel to leave. The departures angered the fans, but Marseille compensated their loss with the signings of talented young players, and the arrival of veterans Lassana Diarra and Abou Diaby.

Bielsa, who criticized Labrune for keeping him away from the recruitment process when he took his job, said this week he was ''satisfied with the squad.''

Bielsa's assistant coach, Franck Passi, is expected to be appointed as interim coach.

Bielsa led Argentina to the Olympic title, and to runner-up in the Copa America in 2004. He also helped Chile qualify for the 2010 World Cup.

At club level, Bielsa guided Athletic Bilbao to the 2012 Europa League final.