Stella Artois, Beck’s and bottled Budweiser will switch from 5% to 4.8% ABV in the on-trade in April. Bud Draught will remain at 4.3%.
The 0.2% change will save 2.5p on the cost of duty for every pint sold.
Citing rising raw material and energy costs, AB InBev implemented a 7.8% price increase across its brand portfolio in January.
While not offering a specific reason for the reduction, AB Inbev confirmed only beer sold in the UK was affected.
In a statement the brewer said: “At AB InBev UK we understand that creating the very best products for our consumers is key to our long term success.
“Our decision to bring Stella Artois, Budweiser [bottles and cans] and Beck’s to the UK market at 4.8% abv during 2012 is in line with evolving UK beer category trends, and we will do so while maintaining the same great taste and quality.
“This latest advance is another example of our commitment to customer focus, quality and offering consumers the widest possible choice.”