A fourth sponsor has withdrawn support for an upcoming concert in Dartmouth, N.S., to be headlined by controversial American R&B singer Chris Brown.

The announcement of Brown as the concert's headline act led to a heated day that saw continuing outrage on social media and even prompted the mayor to vocalize his disapproval of this singer.

Molson Coors Brewing Co., esthetics company Touch of Radiance and the Halifax campus of the Centre for Arts and Technology joined Rogers on Monday in distancing themselves from the Energy Rush summer music festival at Alderney Landing on August 31.

The Centre for Arts and Technology announced on Monday night it was pulling its support.

"As an educational institution, we can't ignore the sentiments expressed on campus that participating in this year's event goes against our collective values," wrote the centre on its Facebook page.

Molson Coors confirmed its withdrawal Monday afternoon.

"Following Friday's announcement we decided to no longer pursue partnership with this year's Energy Rush event. The feedback we've received from fans has echoed our decision not to participate," said Forest Kenney, a spokesperson for Molson Coors in an email to CBC News.

Dartmouth-based Touch of Radiance announced their withdrawal from the concert earlier on Monday.

"In light of the recent announcement of Chris Brown as the headlining act at this year's Energy Rush concert, we have decided pull our sponsorship from this event," read a post on the company's Facebook page.

The esthetics company's statement follows a similar announcement on Saturday by communications giant Rogers that it was pulling its support for the annual Energy Rush at Alderney Landing amid online backlash.

Concert clamor

Brown's upcoming performance stoked outcry on social media.

Those opposed to the show say people in the city shouldn't support Brown, who was convicted of assaulting his girlfriend, pop star Rihanna, in 2009.

"I'm not a big fan of his behaviour in the past, obviously. I think here in Halifax I'd prefer he not be here," said Mayor Mike Savage. "I wasn’t very happy about it."

"I don't think we can stop it. This is an arrangement that's been made contractually between Alderney Landing, the radio station, the promoter and with Chris Brown... I wish I'd have had some input in it beforehand. I think I would have given a fairly strong opinion, but the fact is he's been booked and there are now legal obligations. So I don't like it and I hope people vote with their wallet," said the mayor.

Savage said he's looking into whether there should be a review of how Halifax's facilities book performers.

The Avalon Sexual Assault Centre in Halifax said it appreciates Savage's condemnation and the sponsors' decision to withdraw support.

"By inviting Chris Brown, known for his violent behaviour and assault on Rihanna, to perform here sends a message that if a person is talented, his/her past actions do not matter. Halifax Regional Municipality and the province of Nova Scotia have a critical problem with sexualized violence that needs to be addressed," read a statement.

The promoter behind the concert said he is not surprised by the public backlash but says Brown should be allowed to perform.

"I believe it is a very slippery slope when we start trying to censor, or dictate, who can or cannot perform in this province," said Stephen Tobin, owner of Drop Entertainment Group, in a statement Monday.

"There are thousands of people in the Maritimes who want to see Chris Brown perform. If some do not want to support him, or this homegrown event, they can exercise their right by simply choosing not to attend. But everyone is free to make their own choices and no one has the right to prevent others from having a chance to see this world-class performer, should they choose to do so."

Probation revoked

Brown pleaded guilty to assaulting R&B singer and then-girlfriend Rihanna in 2009. He hit, choked and bit her during an argument in Los Angeles.

Since then, Brown has worked to repair his image, undergoing violence counselling and putting out a new album. He recorded a duet with Rihanna on her recently released record.

He was scheduled to perform at a stadium concert last year in Guyana but cancelled after drawing the ire of women's rights groups and opposition lawmakers in that country over his history of violence.

The controversy in Halifax came as a judge in Los Angeles revoked Brown's probation on Monday after reading details of an alleged hit-and-run accident in May. But Brown was not ordered to go to jail.

Brown's lawyer suggested that perhaps the matter will be resolved informally without a major probation hearing. Another hearing is set for Aug. 16.