Dearden was called into talks with chief executive Stephen Booth and non executive chairman James Derry immediately after the heavy defeat, which leaves the Stags in deeper trouble in the League Two relegation zone.

• Mansfield Town 0 Rochdale 4

Mr Booth, announcing Dearden's departure 'by mutual consent' around 5.20pm, told Chad that today's loss was the final straw for him and his colleagues - including controversial owner Keith Haslam who has promised not to attend Field Mill matches because of fans' protests.

• To listen to Mr Booth and Mr Derry announce the news at a post-match press conference - featuring questions by Chad's Tim Morriss, BBC Radio Nottingham's David Jackson and 103.2's Jason Harrison, click on the green play icon - Thanks to Mansfield radio station 103.2 for the audio

Mr Booth confirmed that he had spoken to Mr Haslam about the decision to change the manager, saying: "He is the majority shareholder and was party to our discussions, of course. He very reluctantly agreed."

Both Mr Booth and Mr Derry stressed after the match that the decision to change the manager had not been pre-planned - but they felt they had to act because of the level of performance and the 'perilous League position'.

• Ex-Stags player tipped to be new boss

The chief executive added after the eighth home defeat in nine games: "We had our best team out today and it didn't happen, so something had to change.

"That capitulation today was the final straw.

"A shortlist of potential new managers has been drawn up and an announcement will be made within 48 hours."

Mr Booth, who promised an announcement on the future manager before Tuesday's match with Hereford, went on: "Bill and I had a full and frank discussion and we agreed that it was in the best interests of Mansfield Town and Bill that we parted company with immediate effect.

"Effectively we have a quarter of the season left. There is money to bring in players and the loan window closes in two weeks.

• Give us YOUR verdict on Billy Dearden

"Billy's a great character. This was a hard decision to make but time is running out," the chief executive said.

Dearden - at 64 the second oldest manager in the Football League - had been at the helm for just over 14 months after replacing Peter Shirtliff at the end of 2006.

But his second stint in charge at Field Mill was a far cry from the success of his first spell as manager.

When he left for Notts County in January 2002, the Stags - who at the time boasted players like Liam Lawrence, Craig Disley and Bobby Hassell - were riding high in League Two and eventually won promotion that season under his replacement Stuart Watkiss.

But six years on the Stags are facing the prospect of dropping out of the Football League and non-executive chairman James Derry told Chad on Saturday night that a new manager had to be brought in.

"We would like to thank Billy for all he has done at the club in very difficult circumstances and wish him all the best for the future," said Mr Derry.

"This is a very sad day but the fans deseve better. The performance today was pathetic, embarrassing to watch.

"We can't continue like this at home and that is why we had to make a change.

"I think he (Billy) accepts the game today was not of a standard that was acceptable.

"We could not let it carry on. For whatever reason the players are playing reasonably well away, but the fans deserve better at home.

"You can't carry on like that. I am not blaming Billy, but you have got to do something to try to change it.

"I don't think any other team in our division could play as well as we did against Middlesbrough so it is frustrating when they play like they did today.

"There are 12 games to go to get out of it. The only good news today was that Macclesfield also lost so we are no worse off."

Relegation-threatened Mansfield have not won at home since the Boxing Day clash against high-flying Peterborough and there were chants of 'Dearden out' during today's game.

There is now speculation that former Rotherham and Sheffield United boss Billy McEwan - who had a spell as a player at Field Mill in the 70s - could be installed as the new Stags' manager.

Assistant manager Paul Holland remains at Field Mill for the time being, Mr Booth confirmed to Chad on Saturday evening.

And on Sunday it was announced that Holland would be in charge of the first team for Tuesday's match against Hereford.

• Holland in charge of Stags for Hereford game

Meanwhile, Mr Derry said he was hopeful of progress in the protracted takeover of the crisis club in the coming days.