Is it permissible to partner with a non-Muslim businessman in a hotel that includes a bar, knowing that I will not participate in the bar's income or have any relation to it, and that the purchase will be gradual until I own the hotel completely?

It is forbidden for a Muslim to drink alcohol, sell it, consume its price, or assist in it in any way, because the Messenger of Allah, peace and blessings be upon him, cursed ten individuals concerning alcohol. It is not permissible to rent out property to someone who will use it to sell forbidden items, such as alcohol, as that constitutes assistance in sin.

If you are to buy a hotel that has a bar for selling alcohol, and you did not participate in its rent, nor benefit from its revenue, and have no relation to it, then it is permissible for you to purchase, provided that you do not leave any doors leading from the hotel to the bar, as that facilitates disobedience. If the owner refuses to close the doors, then it is not permissible for you to partner with him.

If the bar becomes part of your ownership after purchase, then it is obligatory upon you to close it and cancel its lease contract. If there is a fixed-term lease contract that you cannot terminate, then either postpone buying the part related to the bar until the lease expires, or buy the entire building with the previous lease belonging to the first owner, and deduct the value of the lease from the purchase price.