What is the ruling on working for financial leasing companies?

Dealing with financial leasing companies that sell equipment in installments takes two forms: The first is permissible, which is selling in installments at a higher price than cash without penalty clauses for late payment. The second is forbidden, which involves stipulating the return of the item or a financial increase upon late payment. It is not permissible to work in carrying out this transaction because it involves cooperation in sin, unless the work does not pertain to these deals.