"We've made a tough decision today," said chief executive Tod Leiweke in a statement. "It became apparent after conducting an extensive internal audit that a new direction was needed to provide an opportunity for the organization to be successful."
According to the league's website (http://www.nfl.com) Minnesota Vikings defensive coordinator Leslie Frazier has been contacted about an interview with Seattle, which has not reached the playoffs since the 2007 season.
Mora, who joined the Seahawks in 2007 as a defensive backs coach, took charge of the team when Mike Holmgren stepped down after compiling a 4-12 record in the 2008 campaign.
"This team, more importantly this community, means so much to me that it hurts not being able to see this through," he said.
"I am disappointed I did not get the chance to complete my contract. This is a tough business that sometimes demands immediate gratification."
(Writing by Larry Fine in New York and Frank Pingue in Toronto, editing by Tony Jimenez)