Slade joined Grimsby in May 2004

The club, who lost in the final of the League Two play-offs, released a joint statement citing a failure to reach a contractual agreement.

The statement read: "The board would like to put on record that Russell leaves the football club in an excellent position.

"In particular we have had an excellent season and Russell will be remembered for those good times."

The club added they would "appoint a new manager as soon as it is practically possible".

The Mariners' 1-0 defeat to Cheltenham on Sunday consigned them to another season in the bottom rung of the Football League.

The day after their Millennium Stadium defeat, chairman John Fenty issued an ultimatum to Slade after the pair failed to agree on terms for a new deal.

Slade, whose contract ran out this summer, took over the club before the 2004-05 campaign after nearly three seasons at Scarborough.

The Mariners finished 18th in his first season in charge but he led them to fourth in the table this year.