Is there any doubt in dealing with banks that are established, and whose owners say that they invest the deposits in projects

The questioner:
In one of the Islamic countries, they established banks for Islamic transactions that follow the state, and they write on the papers , and they say, "We invest the deposits in productive Islamic projects, and we credit the account every three months, and we determine the depositor's share at the end of the period, and this share varies at the end of each period, sometimes increasing and sometimes decreasing. Is there any doubt in this?"

The Shaykh:
If it is based on an Islamic mudarabah (profit-sharing partnership), and it gives the partner a known share of the profit, a quarter, a fifth, a half, or so on, these are lawful transactions, called lawful mudarabah. We hope that Islamic banks will open soon, if Allah wills, in this country,

The presenter:
or what comes before that.

The Shaykh:
The gambling with the authorities will be abandoned soon.

The presenter:
May Allah bring about good.