The 28-year-old has joined the Highbury staff following a string of impressive displays in the Champions League.

"Pascal is a fantastic defender with great ability and has proved that he can compete at the highest level from his performances in the Champions League," said Arsenal boss Arsene Wenger.

"He is an extremely constant player and will fit in very well at Arsenal. I am very positive he will be a fantastic asset to the team."

Cygan, who takes over the number 18 shirt formerly worn by fellow Frenchman Giles Grimandi, said: "I am very excited about joining Arsenal.

"They were the top team in England last season and I'm hoping to help them finish first this year.

"I am also looking forward to working with Arsene Wenger, who is recognised as one of the best coaches as well as being part of a squad with many world-class players."

Cygan, at 6ft 5ins, is seen as an ideal replacement for club captain Tony Adams, who is thought to be considering retirement from the game after 20 years at Highbury.

Following Lille's promotion to Le Championnat top-flight as second division champions in 2000, Cygan has been a vital member of a side that has challenged the established order in French football.

He was voted best player in the French first division by journalists with France-Football magazine in 2000/2001.

Meanwhile, Arsenal defender Martin Keown has ended the uncertainty over his future by signing a new two-year contract.