Edit: it was once a prescription of the Catholic Church that there was an explicit prohibition against the charging of interest or usury. This expectation has been modified. Usury wasn't prescribed by the early Church and it wasn't systematically condemned by the Fathers, but it became so beginning in the ninth century.
There still seems to be an injunction against usury or ruinous interest charged on non-productive loans, but it isn't discussed and many people don't understand why this ancient prohibition, going back to the ancients themselves, isn't more widely discussed these days by church authorities.
The Muslims don't lose any opportunity to capitalize on opportunities to discuss the problems with usury, and have even created alternatives to paying interest on loans by solutions like the following which apparently allow a devout Muslim borrower to share the risk with his lender in a real-estate transaction.
The increasing popularity of these programs, coupled with relative indifference on the part of Catholic church leaders on these matters, should raise some concerns about the growth of Islam and the growing significance of its legal structures in Western countries.