The Ruddles brewery in Rutland is likely to be closed some time next year following its takeover by Oxfordshire brewer Morland.
Morland bought Ruddles last week for up to £8.4m in a complex deal involving trade liabilities and stock. The brewer paid £4.8m for the Ruddles brand and agreed to take on trade liabilities of £1.4m.
The brewer will boost marketing for Ruddles' beer brands but production could shift to Morland's Abingdon headquarters. The future of the Ruddles brewery is under review.
A further sum of up to £2.2m may be paid in February in respect of any stock utilised by then.
Morland said it would carry out a review on how to integrate the two businesses.
Chief executive Mike Watts said: "We are delighted to be adding the respected Ruddles brand to our business.
"The acquisition continues our strategy of developing our brands and brewing business by concentrating on our niche products."
He promised to back the new brand with significant marketing to boost sales in Morland pubs and in the freetrade.
Ruddles County and Ruddles Best continue to sell well in the off-trade but sales have been declining in pubs.
Morland brand and brewing director Rupert Thompson said: "There are also significant export opportunities, particularly in North America and Europe."
"Morland flagship ale Old Speckled Hen is already doing well in these markets."
Sources at other breweries felt it was almost inevitable that Ruddles would be closed down. One senior brewer said: "It seems we are losing a few breweries this year.
"There is some rationalisation going on this year and I think the Ruddles situation is part of that.
"I do not think that there is much hope that the brewery will stay open."
Brewers Gibbs Mew and Eldridge Pope quit brewing earlier in the year to concentrate on pubs.
Ruddles campaigned successfully for the independence of Rutland as a county - this year it was granted the right to leave Leicestershire to become the UK's smallest county with fewer residents than Slough, in Berkshire.
But Ruddles itself has not been independent since 1986, when it was sold to Grand Metropolitan before moving to Dutch brewer Grolsch.