Is it permissible to give a certified check to a person who will withdraw an amount of 34,000 Libyan dinars and take a commission ranging between 1% and 2% in return for providing cash liquidity, which is unavailable in Libyan banks?

It is not permissible to sell a check for less than its value, because that involves usury of excess (riba al-fadl), usury of delay (riba al-nasi’ah), and uncertainty (gharar) if the check is not guaranteed or is post-dated due to insufficient funds or liquidity.