The claim, which is extremely unlikely to come true since the Office of Fair Trading will not currently let any company own more than 25% of pubs in any one licensing district, was made at the launch of the 30th edition of Camra's Good Beer Guide.
Other predictions for the year the 60th edition is due include:
A pint of beer could cost up to £25
Only two major brewers will dominate beer sales with just two beer brands each
Nearly 8,000 local community pubs will have closed, many becoming private houses
Six out of ten pints beer will be drunk at home with people enjoying a pint in 'virtual pubs' while sitting in their own arm-chairs
Small specialised breweries selling local real ales will have grown in number by 40%, to 600, though they will still take only a tiny share of the total market.
Camra is urging the government to act to halt what it claims is growing anti-competitiveness by the large pub chains and global brewers, to prevent many of its fears from becoming a reality.
Roger Protz, editor of the Good Beer Guide, said: "If we want to continue to enjoy the great British pint in local pubs of the future, action needs to be taken by the government now, in the form of a national strategy to deal with growing anti-competitiveness by the large pub chains and global brewers."