Is a partnership permissible in Islamic law where profits and losses are divided equally (one-third for each partner), while financial contributions are not equal and one of the partners may contribute only through work?

It appears that this company is permissible. It is permissible for a body and capital to combine, or for two capitals and a body, with the profit shared among the partners according to their agreement, and the loss borne by the owner of the capital in his wealth, and by the owner of the body in the waste of his effort and toil. This partnership is a Mudarabah if the two partners hand over their capital to a third party to work and engage in Mudarabah with it. However, if the two owners of the capital stipulate the participation of the owner of the body in the work, then it is not a valid Mudarabah according to Malik and Shafi'i, but it is valid according to Ahmad, and this is the preferred view, because the default rule in transactions is permissibility.