All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
Amongst the permissible bilateral partnerships is the Mufaawadhah partnership (unlimited partnership) in which each party authorizes the other to handle freely every aspect of the capital and labor of the partnership such as buying, selling, speculating, authorizing, and purchasing through credit and the like.
Your question indicates that the partnership between the two of you is of that kind. If this is the case, then the rights of the contract of that partnership are equal for both partners.
Accordingly, both of you have to pay those debts. Saying that your partner is the one who took them does not count. Rather, you can pay off the debts without a special permission from your partner. However, if the debt is due and the debtor does not ask for it, it is not obligatory to pay it off immediately. Zakariyya Al-Ansaari said: "The solvent should pay off his due debt immediately as much as he can if he is asked for it because the Prophet, sallallaahu ‘alayhi wa sallam, said: “The rich (solvent) who delays payment of a debt is committing wrongdoing.” [Al-Bukhari and Muslim] It cannot be said that someone delayed payment except if the debtor asked for it and he did not pay him. However, if he did not ask for it, it is not obligatory to do that."
Accordingly, it is not obligatory upon you to hasten to pay off that debt for the matter has no specific time, i.e. it could be delayed. We see that you should discuss that matter with your partner kindly to convince him to pay the price of those commodities to their owners and clear himself of their rights, or rather you may get benefit of that available money in your trade since the matter has no specific time. What is really required in your partnership is to agree with one another and not dispute for this is more appropriate to make you prosperous and successful.
When paying the debt, you have to do the following: To pay to the one from whom you took money. As for the agents of the companies who adjusted debts to be paid to their companies, then paying them to those companies is obligatory. It is not permissible to give them in charity as long as paying them to their owners is possible. Your assumption that some mistakes may occur while paying them is irrelevant for this may be avoided by many ways.
As for what you have mentioned about your inability to pay off all those debts in one stroke, then you may wait until you have money for paying them off, since payment does not have to be immediate as we have stated previously. Also, you can pay them off in installments by paying what is available until you pay them all.
Allaah Knows best.