"I'm absolutely delighted to be fighting to achieve something special with this club," Vardy said in comments published on the club website.

"I've never known a spirit like it -- from the owners, to the manager and his staff, the players and the fans. I want to be part of it for a long time."

Vardy, 29, played a key role as Leicester stunned Manchester City 3-1 at the Etihad Stadium earlier on Saturday to open up a five-point lead at the top of the Premier League table.

Along with Algerian winger Riyad Mahrez, the indefatigable Vardy has become a symbol of Leicester's rise from the foot of the table to the summit over the past 12 months.

Signed from non-league Fleetwood Town for £1 million ($1.4 million, 1.3 million euros) in 2012, he is the Premier League's top scorer with 18 goals and has become an established member of Roy Hodgson's England squad.

Vardy added: "Leicester City have shown nothing but total faith in me since the day I arrived here three and a half years ago and it's impossible to measure how much that belief has helped me to improve.

"I'll forever be grateful for the investment the club has made in me and I'll spend every day working to repay it."

Leicester manager Claudio Ranieri said: "Jamie is a fighter. He has had an unbelievable journey to get to this point in his career and continues to play every game as if it's his last.

"I love his spirit, which is a quality I want in my players above all else. He has shown what a fantastic player he is and, more importantly, he is part of a fantastic group.

"I am very happy that he will stay with us for a long time."