Two pubs are closing in Britain every day, reflecting a "perfect storm" of tax increases, cheap supermarket promotions and lack of support for licensees, according to a report.
A study by the Campaign for Real Ale (Camra) found that almost double the number of pubs which are "tied" to a company - so-called pubcos - are closing compared to others.
Camra said tied pub licensees were prevented from buying beer on the open market, having to pay up to 45% more than their competitors.
"The number of tied pubs has fallen by 3,216 since 2008 as the large pub companies have failed to support their licensees through tough times.
"The positive news, reflected in the Good Beer Guide, is that the number of free of tie pubs actually increased in number by 425 over the same period," said Camra.
Roger Protz, editor of the Good Beer Guide, said: "These figures show a spiralling decline in the tied pub sector, brought about by big pubcos squeezing their licensees with high beer prices and creating an environment where many publicans are unable to invest in their businesses.
"While many tied publicans struggle in the face of high rents and excessive beer prices, free of tie owners are faring better in the current climate with the ability to offer greater beer choice, lower prices and a better pub environment to the consumer.
"Free of tie pubs, managed pubs and tied pubs run on a more sustainable basis by the family brewers are much more likely to survive and continue serving communities long into the future."
Camra called on the Government to introduce free market reforms to help save the nation's pubs.
Paul Maloney, national officer of the GMB union, said: "Jobs in pubs are being lost needlessly every day. City financial engineering has pushed the price of a pint 80p higher than justified by inflation, pushing local pubs out of business. Everything the City touches involving the public seems to have the Midas touch in reverse."