Longman Dictionary of Contemporary English:
mortgage [countable]

1. a legal arrangement by which you borrow money from a bank or similar organization in order to buy a house, and pay back the money over a period of years:
Your building society or bank will help arrange a mortgage.
They've taken out a 30 year mortgage (=they will pay for their house over a period of 30 years).
We decided to use Fred's redundancy money to pay off the mortgage (=pay back all the money we borrowed for a mortgage).
Mortgage rates are set to rise again in the spring.
She was having trouble meeting her mortgage payments.

2. the amount of money you borrow in the form of a mortgage:
If you earn £20,000 per year, then you may be able to get a mortgage of £60,000.

Jeśli więc chodziłoby o postępowanie związane z kredytem, to "land and mortgage register proceedings" może by się nadawało - wyrażenie to jest w Google, ale niestety tylko na polskich stronach. Przy sporze o np. tytuł własności proponuję określenie jak w nagłówku.