Companies don't go bankrupt in the UK. Individuals declare bankruptcy. Corporate entities go into dissolution or receivership and the company's assets are controlled by the Official Receiver. Generally, an OR has no idea about domain names unless the company directors either declare it, or have it on their balance sheet; therefore the name will drop according to (in this case) Nominet's cycle. Expect this to change as ORs become aware of the value of domain names and start waking up to the prospect of selling them off for the benefit of the creditors' pool.
Normal practice is for principals not to "mention" the domain assets and then quietly move them to "new" owners.
So, if you want to check out this market in the UK, look in the "London Gazette" and contact the OR's office.