Building understands that five directors and managers are taking their case to an industrial tribunal in Bristol next month.
Up to 20 other former Beazer staff are considering going to an industrial tribunal, and a separate group has hired lawyers to negotiate better deals with Persimmon.
The disputes between the directors and Persimmon centres on back pay and pension entitlements.
The directors claim they are owed nine months' salary and pension contributions. They say they have been offered £25,000 on average but argue that they are each entitled to another £20,000.
The average salary for regional directors was about £50,000, and the total claim could reach £400,000 for salary losses.
Another group of long-serving directors is fighting for full pension payouts. They say that their conditions of service stipulated that if their employment was terminated within 10 years of retirement at 65, they were entitled to a full pension. With these costs, the claims against Persimmon could run into millions.
Persimmon refused to comment on the issue. A spokesperson said: "These are confidential matters."
The firm has set aside £12m for the integration of Beazer, but this may rise if the claims are successful.
One former Beazer director said: "We may be talking millions of pounds in total claims. You can see why they want to do it."
Persimmon cut 660 jobs and closed 12 offices after the takeover. About 65 of the 100 directors at Beazer lost their jobs, and about one in three of them is now in dispute.
Some of the directors claim that Persimmon has been trying to cut its payouts after discovering that the performance of Beazer's upmarket Charles Church brand was worse than it thought.
One said: "Persimmon was horrified by the poor performance at Charles Church and because of that is trying to cut costs at any point – and it is starting with us."
Persimmon admitted last month that there were problems at Charles Church, particularly at one site in south-west London.
Last month, Persimmon chief executive John White said the group had handled the takeover properly. He said: "We have been intent on being straight with people, and fair."
Persimmon said it would update investors on the integration process when its interim results were released later this month.