Brewer took over from Jason Robinson in April
Sale have sacked head coach Mike Brewer and put academy coach Pete Anglesea in charge until the end of the season.
Former All Blacks forward Brewer took over as head coach from Jason Robinson in April but the Sharks have struggled in the Premiership and are 10th.
They have lost four of their last five matches in all competitions.
"I'm personally very disappointed that this has not worked out," said club owner Brian Kennedy. "I wish him all the best for the future."
The 47-year-old took over at Edgeley Park after a stint as Scotland forwards coach, where he was overlooked as head coach for the national side when Frank Hadden departed.
But Brewer has managed only three wins out of nine games for Sale this term.
Despite six defeats so far this season, Kennedy said he was confident that Anglesea would steady the side's season.
"He is the obvious choice to lead the team in the short term," Kennedy said.
"He has been part of the club for many years as a player and his coaching record this season with the Jets and the LV= Cup squad is exemplary and he has yet to taste defeat.
"We will now undertake a thorough search to secure the best coaching team and structure for the future."
Sale have struggled with injuries in recent weeks, with David Seymour, Mathew Tait, Eifion Roberts, Tom Brady and skipper James Gaskell all suffering lay-offs.
We have a set of established internationals plus the desire to make a number of key new signings over the next six months
There has also been speculation over the futures of England fly-half Charlie Hodgson and prop Andrew Sheridan, while the club has struggled in both the Premiership and Challenge Cup competitions.
But Kennedy said he remained confident that the side would improve, adding: "We have a superb crop of young players coming through the academy.
"We also have a set of established internationals plus the desire to make a number of key new signings over the next six months."
Anglesea will be assisted by new forwards coach Steve Scott, current backs coach Byron Hayward and defence coach Graham Steadman.
His first match in charge will be the trip to Welford Road on Monday to face Premiership champions Leicester.