Ruling on raising the price of a product in order to extend the warranty

What is the ruling on raising the price of a product in order to extend the warranty?

Praise be to Allah, and blessings and peace be upon the Messenger of Allah:

We put this question to Shaykh ‘Abd-Allaah ibn Jibreen, may Allaah preserve him, who replied as follows:

There is nothing wrong with it if it is done with the agreement of both parties… but selling separate warranty certificates is not permitted. And Allaah knows best.