Arsenal have signed French international midfielder Samir Nasri on a four-year contract from Marseille.
The highly-rated 21-year-old joins for an undisclosed fee.
"I am very happy to become an Arsenal player, it means such a lot to me," he said.
"This is a very important step in my life as a football player because Arsenal is a massive club.
"I really hope everything will go well for me here. I will try my best for Arsenal and its fans and I am honoured to be part of such a great football club."
Arsenal manager Arsene Wenger is thrilled with the acquisition, which reinforces his reputation for luring the best young talent in Europe to North London.
"We are delighted to be signing Samir Nasri. He is young, quick and technically an outstanding player," he said.
"He has shown great potential with his performances for Marseille and the French national team over the past two seasons and he will add great quality to our squad."
A further bulletin on Nasri's website apologised to Marseille fans.
