Thousands of former Dairy Crest milk providers will have to make do with a small pension increase.
They are between 15 000 members of the company to the pension plan, who have been sent letters giving details of the cuts.
Until now, a pension, based on his final salary, have increased each year in line with the Retail Prices Index (RPI) to measure inflation.
In the future, the increase will be to follow the Consumer Price Index (CPI).
This measure tends to be about a percentage point less.
In the state of things, the plan of Â£1 billion of investment will not be sufficient to cover its future pension bills.
But Dairy Crest will report an extraordinary gain of â‚¬ 125 million in its accounts, because of the move.
And it will reduce its cash contributions by Â£12m per year for two years.
The president of the trustees of the pension plan, Vicky Companion, told the BBC that the system of rules has allowed the switch.
She said that the company had made commitments to maintain future contributions, and that the changes “, the fund on a more solid basis for the future”.
Approximately 8 400 members are already in the midst of their pensions. The others are still at work, or waiting to reach the age of retirement.