Beamish & Crawford will transfer its licence to brew Carling lager to Bass Brewers in May 2003.
The Cork firm yesterday said it would continue to brew Carling until April 2005, when Bass would decide on the future of the product.
Beamish's managing director, Mr Alf Smiddy, said the move would not lead directly to job losses.
But he added that global consolidation in the beer business meant cutbacks were inevitable. For example, 12 staff would lose their jobs this year because Beamish planned to use a national distribution centre. The Carling brand conflicted with the Beamish range of lagers which included Foster's and Millar Genuine Draught, he added.
"In terms of Carling as a brand, in many respects it's probably the oldest swinger in town."
While Millar was a "premium product", Carling was sold in off-licences as a less expensive product.
When asked whether the transfer would affect Beamish's revenues and profits, Mr Smiddy said: "Clearly we have revenues but we also have a lot of costs in terms of marketing, sales and promotion."
Because Beamish's competitor Bass brewed Carling in Britain, Mr Smiddy said it was difficult to co-ordinate promotion of the brand.
Tennants Ireland, owned by Bass Brewers, said the brand would be sold throughout the island by the company.
Its managing director, Mr Liam Meaney, confirmed it would assess the brand in 2005.
Carling was "very strong" nationally when sold in cans, he said. The bottled product was strong in the south-east particularly in Waterford and draught beer was strong throughout Munster.
"I think we would expect volumes to be maintained at a minimum," he added. Bass would "work closely" with Beamish to ensure its success.