Greene King's £272m acquisition of Nottingham's Hardy & Hansons last week has heightened concerns that independent brewers have lost the battle against bigger rivals.
In the past two years alone, Greene King and Wolverhampton & Dudley have swelled their estates to well over 2,000 pubs each through nine separate deals.
Independents swallowed up include Ridley's, Belhaven, Burtonwood and Jennings.
Analyst James Dawson from Charles Stanley Securities said companies such as Fuller's, Young's and Shepard Neame now looked vulnerable.
Paul Hickman, an analyst at KBC Peel Hunt, added that a combination of escalating utility costs and low interest rates, making the sector attractive to private equity backers, was driving the tidal wave of consolidation.
"Scale is the only way to mitigate cost pressures," he said. "If you're a smaller player you need something that sets you apart if you want to survive."
In recent months London's Young's has said it intends to combine its brewing operation with Charles Wells and Fuller's has bought rival Gales. Last week Honeycombe Leisure also put itself up for sale.