Is it permissible to purchase a portion of an employee's right from a company (25,0 out of 37,0) for a larger amount (50,0 Egyptian pounds), knowing that the company has not paid his dues and he is outside the country, and that the questioner previously took money from the company without its knowledge?

If the company does not pay your salary and the delay is prolonged, and you find no means to obtain it, then there is no sin in taking only your right from the company's money without any increase. This is known as the issue of al-Zafar (taking one's right when denied). However, it is not permissible to take more than your right to give to other employees, because that is considered an transgression, and you must repent and return the excess to the company. As for purchasing an employee's debt from the company at an accelerated price less than its value, this is impermissible, as it falls under riba al-fadl (interest due to excess) and riba al-nasia (interest due to delay). You must return the value of the equipment you took to the company if it has given you your delayed rights, and you must find a way to return it to the company, even without its knowledge.