Belhaven brewery shareholders have until September 14 to decide whether to sell the Scottish company to the Suffolk-based brewing giant Greene King for £187m.
Belhaven's directors have already accepted the offer for the 0.5% of shares they hold and recommended that other shareholders do the same.
The 1,500 Belhaven staff were "shocked" by the offer, said Belhaven chief executive Stuart Ross, "but they understand that we've found the perfect partner to move the company forward"
The deal will enable Greene King to sell Belhaven's beers in East Anglia and its own brews in Scotland through Belhaven.
The Campaign for Real Ale, which is petitioning to save Greene King's previous conquest, TD Ridley, from closure this autumn, said: "We are hugely disappointed at the prospect of losing Belhaven, Scotland's largest independent brewery. We support Greene King cask beer -- it may be the best beer in the world, but people like choice"
However, David Liston, senior global beverage analyst at stockbroker Gerrard said that Greene King would not close Belhaven because of its strong brands: "Over the next three or four years, more of these acquisitions will take place and unless the brands are well-known it is likely that they will be closed down."
Meanwhile, St Peter's brewery also hoped to tempt a big buyer when it was put up for sale last month for about £20m. The md Colin Cordy said: "We're hoping a bigger brewery who can see potential in the brand will move it to other production sites as we are unable to cope with demand." The company has a £2m turnover.