Torquay boss Leroy Rosenior has left Plainmoor by mutual consent after three and a half years in charge.
Leroy Rosenior has failed to stem the decline at Plainmoor
The Gulls slipped into the League Two relegation places after a 3-1 defeat at home to Rochdale on Tuesday.
Chairman Mike Bateson told the club's website: "We have decided that a parting of the ways is in the best interests of both parties.
"It's disappointing that it has had to end because Leroy and I had a great working relationship."
The Gulls have found it difficult to adjust to live back in the Football League basement after being relegated last season on goal difference.
Rosenior had led them to promotion the previous campaign.
But, despite reaching the third round of the FA Cup and taking Premiership side Birmingham to a replay, they have managed only three home wins this season and Bateson said it was time for action.
He said: "Leroy has been with us for three and a half years, and we have had some tremendous highs.
"We have also seen a standard of football that has surprised us all.
"I thank him for his efforts and wish him all the best of luck for the future."
No announcement has been made regarding Rosenior's successor.