Arsenal midfielder Mathieu Flamini will join AC Milan on a four-year deal next season after passing a medical in Italy.

The 24-year-old Frenchman, who signed for Arsenal from Olympique Marseille in 2004, will move on a free transfer with his contract at the Premier League club soon expiring.

A team spokesperson said Flamini, who underwent a medical on Monday, would join on July 1 with the deal running out on June 30, 2012.

"I am very happy, thank you very much," he said.

The hard-working midfielder, who played as a emergency left back in Arsenal's run to the Champions League final in 2006, was also courted by Juventus.

Flamini emerged as a key player for Arsenal this season with consistently impressive performances as an energetic, defensive foil for Cesc Fabregas in central midfield.

However, the 24-year-old stalled on signing a new contract and missed Arsene Wenger's final deadline of May 1 to secure a new deal.

"At some stage you have to make a decision and if he goes we have to look at our options," said Wenger.

"We can't wait until July. You could lose players if they come on the market. My ideal solution is that he stays so I am not happy if he goes - but we have done everything we can."

Flamini immediately faces a challenge breaking into a Milan midfield packed with ball-winners such as Gennaro Gattuso, Emerson and Massimo Ambrosini.

Milan chief executive Adriano Galliani denied Flamini has been recruited to replace Italy international Gattuso, who said last week he was considering his future and would like to play in England.

"He is not here to replace Gattuso. He can play across the midfield," Galliani said.

Alex Chick / Reuters