The Halifax bank, Virgin Holidays, The Co-operative Group, Vauxhall and Mitsubishi are among a number of major brands to have cancelled deals with the newspaper in the wake of the latest claims.
Their action follows that of motor giant Ford which said on Tuesday it was suspending its advertising in the Sunday tabloid.
The boycott announcements came as a consumer backlash gathered pace on Twitter with social networkers calling on readers to stop buying the paper entirely.
The Co-operative Group, whose businesses include grocery stores, pharmacies, banking, insurance and funeral services, said the recent claims had been “met with revulsion by the vast majority of members”.
Stressing its “strong ethical standards,” the company said it had opted to “suspend temporarily any further advertising and promotional activity with the News of the World until the outcome of the investigation is known”.
A spokeswoman for Halifax parent company Lloyds Banking Group said the company had decided to pull an advertisement on Sunday in response to “consumer reaction”.
“This was a tactical decision in the short term whilst we carefully consider our longer-term position and its implications,” she added.
Virgin Holidays said it would not be taking up its small number of classified advertising slots this weekend.
The decision follows an announcement by Virgin Group founder Sir Richard Branson who said police had told him he might have been a victim of phone hacking by people working for the tabloid.
Mitsubishi said it had suspended all advertising in the News of the World while the paper was investigated over the Milly Dowler phone hacking claims, while Vauxhall said it had stopped placing adverts in the paper.
On Twitter, media commentator Roy Greenslade wrote: “Boycott News of the World. Tell everyone: ‘stop buying the paper’.”
A similar sentiment was expressed on Facebook where numerous users expressed mounting public anger on the News of the World’s own page, while hundreds joined groups including “Boycott ‘News of the World’ for phone hacking Milly Dowler!”