Cadbury has been criticised by the advertising watchdog for playing on Caribbean stereotypes in a campaign.
The Advertising Standards Authority said its promotion for Trident Gum, which is now over, had caused "deep offence" to a significant minority.
The five adverts featuring a black man and two white people speaking in accents attracted 519 complaints.
Cadbury said the campaign was meant to be a celebration of dub poets who had inspired multi-cultural audiences.
The firm said it had undertaken consumer research and consulted members of the British African-Caribbean community but accepted the watchdog's decision.
"We would never seek to cause offence to anyone and regret if any member of the public felt this was the case," the firm said.
"However, we are disappointed by the ruling because the ads were carefully researched and were also approved by the Broadcast Advertising Clearance Centre (BACC) to ensure they were acceptable."
The ASA found the commercials featuring the catchphrase "Mastication for the Nation" had breached rules on offence and harmful stereotypes.
But it ruled the adverts did not incite racial intolerance or discrimination.
But in its adjudication, the ASA noted Cadbury's own research had found the ads were likely to result in a polarised reaction and about one in five of the British African-Caribbean sample had found the ads offensive.
"Greater sensitivity was required of advertisers using humour based on accents, because of the potential to cause serious offence, especially if it could be seen to be patronising or demeaning to groups of people who were generally recognised to have encountered prejudice," it said.