Gerard Houllier has stepped down as Aston Villa boss with immediate effect.The 63-year-old Frenchman took charge in September 2010 following the departure of Martin O'Neill on the eve of the 2010/11 season.

But former Liverpool manager Houllier endured a turbulent time at Villa Park and suffered a heart scare on April 20 that left him unable to work for the remainder of the season, with assistant coach Gary McAllister taking over the first team in his absence.

Now Houllier intends to take further time off to fully recover, but said he will miss not being part of the set-up at Villa.

"I am extremely disappointed that I will not have the opportunity to manage Aston Villa next season," Houllier said.

"My health has improved considerably since I was taken ill on April 20. I now intend to take the next few months to concentrate on recuperating fully before I may return to football."

"I was very much looking forward to the prospect of my first full season as Villa manager and returning for pre-season training to prepare for the campaign ahead, a luxury that I did not have last season."

"I am very grateful to the Villa fans for their genuine concern and encouragement and to the fans of clubs up and down the country for their kind sentiments."

"I would especially like to thank my assistant manager, Gary McAllister, my staff, the players and all at Aston Villa for their support and, of course, for their efforts in securing a very positive end to last season."

"It has been an honour to manage this great club and I wish everyone connected with Aston Villa every success for the future."

Villa chief executive Paul Faulkner paid tribute to Houllier's service to the club and wished him well in his recovery.

Faulkner also said the club had begun the search for a new manager.

"I would like to thank Gerard for his considerable efforts over the past nine months and for the dedication, commitment and work ethic he has demonstrated as Villa manager," Faulkner said.

"We regret the circumstances of Gerard's departure and, naturally, we wish him well in his continued recovery."

"I know I speak for everyone associated with Aston Villa in expressing our hope that Gerard will return to full health as quickly as possible and we wish him all the best for the future."

"As a board we are very conscious of the need to ensure that the club is prepared fully to meet the demands of the new season and, to that end, we have already embarked upon the process which will lead to the appointment of a new manager."