Carlsberg-Tetley (C-T) has refused to comment on speculation that it is to close its Alloa and Wrexham breweries.
The breweries — thought to be the least profitable of C-T's five main sites — are being looked at in a review of operations.
Analysts say C-T has been left high and dry following trade and industry secretary Margaret Beckett's decision to block its merger with Bass.
It was propped up in the past by its arrangement to supply Allied Domecq pubs.
A new deal starts in December and Allied expects to squeeze an extra £40m out of C-T, which currently demands a premium from Allied.
C-T supplies 1.4m barrels of beer every year to Allied.
Also earmarked for possible closure are some of the 20 distribution sites around the country. A total of 2,000 C-T jobs could go.
Alloa brews Calder's Cream Ale, C-T's answer to Beamish Red and Caffrey's. Production could be moved to Burton-on-Trent.
Wrexham Lager is brewed in Wrexham, Clwyd.
The brand is one of many under review in the current shake-up.
Skol and Castlemaine XXXX are former Allied brands to which Carlsberg is likely to be less sympathetic than it is to its "own" brands.
The Danish brewer recently announced a £10m package to back Carlsberg Lager between now and Christmas (The Publican Newspaper, July 21). See Brands News, page 24.
The review is being conducted by Carlsberg — which will own 85 per cent of C-T by the end of the year.
C-T spokesman John Heywood said: "An announcement is due at the end of August. Nothing has been ruled out."