What is the ruling on business partnership between a man and a woman?

It is permissible for a commercial partnership to exist between a man and a woman who are not mahram, provided there is security from fitnah (temptation/strife) and that the rulings of Sharia and the etiquette of interaction between them are observed, especially if the woman is young. In such a case, it is preferable to have an intermediary between them to prevent fitnah. It is also a condition that both be righteous and known for their goodness, religiosity, and virtue.