Orchard Park, N.Y. ? Mike Mularkey resigned as coach of the Buffalo Bills following a 5-11 season in which the team missed the playoffs for the sixth straight year.

Bills owner Ralph Wilson confirmed the decision Friday at a news conference, saying he was surprised by Mularkey’s sudden change of mind. A week earlier, Wilson said Mularkey would return for the 2006 season.

“I was completely surprised by his statement. He seemed very firm about it,” Wilson said. “Now, we’re going to go forward and look for a new head coach.”

Mularkey was 14-18 in two seasons and had three years left on his contract. The move leaves the Bills searching for their third coach in five years.

This is the longest the Bills have been out of the playoffs since the AFL team joined the NFL.

Mularkey’s resignation comes a week after Wilson shook up his front office while announcing that Mularkey had been retained. Wilson hoped to limit the major changes to firing team president and general manager Tom Donahoe and hiring Hall of Fame coach Marv Levy as GM. The Bills also fired five assistant coaches.

Wilson said Mularkey expressed concern about Bills fans who criticized him last year. Mularkey also privately expressed concerns how his family was adjusting to the spotlight in a football-first community.

And, despite Wilson’s assurances, Mularkey’s future beyond next season remained in doubt. The uncertainty would have made it difficult for the coach to hire experienced assistants.

“I did not reach this decision lightly,” Mularkey said Friday. “But after much thought, I have concluded that for my own personal reasons and in the best interests of my family, on balance, outweigh any future benefits that may accrue to me by continuing in this position.”