Jeff Stelling is to leave Countdown after less than three years on the Channel 4 show.
Jeff - the fourth presenter to front the station's longest-running show - will leave at the end of the year to concentrate on his presenting role at Sky Sports.
"I've actually resigned from Countdown so I'll be finishing with that at the end of December," he said in an interview with Tenerife radio station Oasis FM.
"You know, you've really got to have your priorities and my priority is football, I love it, and Soccer Saturday, so I've committed myself very much to that next season," he said.
Channel 4 said it has already begun discussions to find a replacement to host Countdown, along with maths whiz Rachel Riley.
The longest serving host was Richard Whiteley who launched the show at the birth of the channel in November 1982 and continued until his abrupt death in 2005. He was replaced by Des Lynam who lasted less than two years, unhappy with the journey to Leeds for filming the daily afternoon word and maths contest.
Jeff, who joined the series in early 2009, replacing Des O'Connor, said he would miss working with Rachel, who replaced Carol Vorderman.
"That'll be really really sad. I've got a few moments of it yet contractually - but she's a great girl by the way, even though she's a Manchester United fan. She's a genuine football fan which is great.
"We have some great times. No, I'll miss her, but I just felt I had to really try on focus on the things that I love which are football and Soccer Saturday," he told the station.
A spokeswoman for Channel 4 said: "Jeff will continue to present Countdown until the end of the year. He's had a brilliant three years on the show and we're sad to see him go. We're already talking to a number of people to find a replacement."