What is the ruling on a factory owner granting a percentage of the sales of his products to another person, with the latter guaranteeing the payment of the sales value from the benefiting companies, knowing that one of these companies employs the marketer? And what are the Sharia-related caveats in this transaction?

The transaction mentioned involves several Shariah prohibitions:

Firstly: Taking compensation for influence (جاه) to guarantee the buyer. Some scholars have absolutely forbidden it, while others have absolutely disliked it. Some have elaborated, permitting it only if the person providing the influence needs expenses and effort, and takes a customary fee; otherwise, it is forbidden. This last detailed opinion is the one adopted for fatwa. However, if the guarantee is merely for collecting the price from the buyer, then there is no harm, and the contract would be for brokerage.

Secondly: Making the brokerage fee a percentage, due to the ambiguity (جهالة) and uncertainty (غرر) involved.

Thirdly: The broker being an agent or employee of the buyer, in which case it is not permissible for him to take a commission from the seller due to the suspicion of favoritism. Also, he is not permitted to exploit official working hours for purposes other than his job without permission.

Therefore, this work is not permissible. It is advised to fear Allah and strive diligently in seeking provision.