Greene King, the brewer and pub operator, is thought to be eying the McMullen's brewery in Hertford.
Speculation is growing within the industry that the company is about to launch a £68m bid. It is thought any deal would not be revealed until after Greene King announces results in July.
A McMullen's spokesman said the company would not comment on what may or may not happen.
The deal would give £585m Greene King additional brewing capacity for its expanding portfolio of beers including Ruddles and Speckled Hen.
The company is a prominent player in the real sector. Its session beer IPA is No.2 in the market, Abbot Ale is No.3 in the premium end and Speckled Hen is No.1 in the take home market.
The company has also grown Ruddles by 20 per cent since it took control of the brand from Morelands.
Any deal would see the 135 pubs remain in the hands of the McMullen family. The combined value of McMullen's brewery and pub interests is thought to be about £200m.
Directors at the family-owned company, led by David McMullen, are split over the decision to sell. Some want to realise their holdings while others wish to remain with the business.
Despite the uncertainty the company is seeing best-ever trading figures. It is opening two more Baroosh café-bars, in Uxbridge and Cambridge, following Hertford last year.
Bury St Edmonds-based Greene King is already thought to be in exclusive talks with Morrells of Oxford, a process that could see it buy the £65m company.
It beat off stiff competition from rivals Punch and Pubmaster. Morrells has 123 pubs - 67 managed and 56 tenanted.
The company's pubs are best known as the favoured choice of Inspector Morse. Its pubs were regularly featured in the popular detective series set in Oxford.
The company's beer brands, which are contract brewed by Thomas Hardy, include Graduate and Varsity. The deal would see the Greene King estate grow to about 1,950 pubs.
The company has been on the acquisition trail in recent times. Last September it bought Old English Inns for £102.8m.
More recently it made its first foray north of the border with the Dalgety Taverns deal. The company is taking its value food concept Hungry Horse to Scotland.
Greene King in for £65m Morrells (16 May 2002)